User:Polygon/Collection of BB Champions

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A collection of Busy Beaver Champions including Champions for BB-Adjacent functions. Note that for all functions with the input format f(n,m), n denotes the number of states and m denotes the number of symbols of the relevant Busy Beaver domain. Note that for functions with this input format f(n) = f(n,2).

State-and-Symbol-Limited Busy Beaver functions

Busy Beaver functions where the programs size is limited by the amount of states and symbols.

Original Busy Beaver Functions

Maximum Shifts Function (S(n,m), also commonly called BB(n,m))

Maximum amount of steps a Turing machine with n states and m symbols can run for before halting when started on the blank tape.

2 Symbols: Runtime Champions Reference
BB(1) 1 1RZ--- (bbch)
BB(2) 6 1RB1LB_1LA1RZ (bbch) 1RB0LB_1LA1RZ (bbch) 1RB1RZ_1LB1LA (bbch) 1RB1RZ_0LB1LA (bbch) 0RB1RZ_1LA1RB (bbch) [1]
BB(3) 21 1RB1RZ_1LB0RC_1LC1LA (bbch) [1]
BB(4) 107 1RB1LB_1LA0LC_1RZ1LD_1RD0RA (bbch) [1]
BB(5) 47,176,870 1RB1LC_1RC1RB_1RD0LE_1LA1LD_1RZ0LA (bbch) [1]
BB(6) > 10 ↑↑ 10 ↑↑ 10 ↑↑ 8.10237 1RB1RA_1RC1RZ_1LD0RF_1RA0LE_0LD1RC_1RA0RE (bbch) [2]
BB(7) >3↑203>fω(20) 1RB0RG_1RC1RB_0RD1RZ_0LE0LD_0LF1LE_1RA1LF_1LC0RB (bbch) [3]
BB(8) >fω3(12) 1RB0RA_1LC1LF_1RD0LB_1RA1LE_1LH0LC_1RG1LD_0RG0RF_1RG1RZ (bbch) [4]
BB(9) >fω7(12) 1RB0RA_1LC1LF_1RD0LB_1RA1LE_0LH0LC_1RG1LD_0RG0RF_0LI1RZ_1RI1RC (bbch) [5]
BB(10) >fω+1(2↑363)>g64 1RB0RA_1LC1LF_1RD0LB_1RA1LE_1LI0LC_0RG1LD_1RH1LG_1LC0RG_0LJ0LI_1RZ0LC (bbch) [6]
BB(11) >fω+1(fω2(5)) 1RG0LH_1RK1RC_0LD1LA_0RE1LD_0LI1RF_1RZ0RG_1RB1RG_1LA1LH_0LK0LJ_1LH1LI_1LJ1RE (bbch) [7]
BB(12) >fω+2(fω+12(3)) 1RB1RA_1RI1RC_0LD1LG_0RE1LD_1LK1RF_1RG0RA_1RA0LH_1LG1LH_1RE0LJ_1LH1LI_1RZ0LL_0LH1LK (bbch) [8]
BB(13) >fω+26(fω+12(3)) 1RB1RA_1RI1RC_0LD1LG_0RE1LD_1LK1RF_1RM0RA_1RA0LH_1LG1LH_1RE0LJ_1LH1LI_0LL0LL_0LH1LK_1RZ0LH (bbch) [9]
BB(14) >fω+3(17) 1RB1RA_1RI1RC_0LD1LG_0RE1LD_1LK1RF_1RM0RA_1RA0LH_1LG1LH_1RE0LJ_1LH1LI_0LL0LL_0LN1LK_1RZ0LH_0LG1LJ (bbch) [10]
BB(15)
BB(16)
BB(17) >fω+33(9) 1LB1LA_1RC0LA_1RD1RC_1RE1RK_1RF0LJ_1LG1RI_1RM0LM_1LG0RC_0RN0LE_1LA1LE_0LL1LB_0RM1LL_1LF1RH_1RQ0LO_1LP1LN_0RB1LI_1RZ1LO (bbch) [11]
BB(18) >fω+4(228) 1LB1LA_1RC0LA_1RD1RC_1RE1RK_1RF0LJ_1LG1RI_1RM0LM_1LG0RC_0RN0LE_1LA1LE_0LL1LB_0RM1LL_1LF1RH_1RQ0LO_1LP1LR_0RB1LI_1RZ1RR_1RN0LO (bbch) [12]
BB(19) >fω+72(5) 1RQ1RL_0LI1RC_0LD1LF_0RA1LD_1RB1RE_1LH0LG_1LF1LG_1RE1RM_1LJ1LI_0LK1LI_1RL1RA_0RL0RE_0LN1RM_1LO0LO_1RE1LP_1LN1LN_1LR1RQ_1RZ1LS_0LE0LR (bbch)
BB(20) >fω×2(fω+22(f10(2))) 1LH0LG_0LI1RC_0LD1LA_0RE1LD_1RQ1RL_1RB1RF_1LA1LG_1RF1RM_1LJ1LI_0LK1LI_1RL1RE_0RL0RF_0LN1RM_0RF0LO_0RF1LP_0RF1LN_1LR1RQ_1RZ1LS_0LF1LT_0LF0LR (bbch)
BB(21) >fω22(4↑↑341) 0LI0LF_0RJ1RG_0RD1LC_1RH1RE_1LO0RH_1LA1LF_0LC1LA_1RB1RH_1RD0LF_1LP0RK_0LM1LL_0LL1LM_1LE1LN_0RQ0LM_0RP1LO_1LR0RH_1LF1RQ_1RZ0LS_1LH0LT_1LH1LU_0LE1LR (bbch) [13]
BB(29) >fωω(3) [1] [14]
BB(31) >fω↑↑4(3) [2] [15]
BB(33) >fω↑↑6(3) [3] [16]
BB(48) >fε0(fω+1(fωε0+1(fω2(fωωε0+1(fω3(fε1(3)))))))>fε1(3) [4] [17]
BB(150) >flim(BMS)(10↑↑15) too large to show [18]
BB(1015) >D5(99) = Loader's Number
3 Symbols: Runtime Champions Reference
BB(1,3) 1 1RZ------ (bbch)
BB(2,3) 38 1RB2LB1RZ_2LA2RB1LB (bbch) [1]
BB(3,3) ≥119112334170342541>1017 0RB2LA1RA_1LA2RB1RC_1RZ1LB1LC (bbch)
BB(4,3) >2↑↑↑2↑↑↑2↑↑↑(7.92×1028) 1RB1RD1LC_2LB1RB1LC_1RZ1LA1LD_0RB2RA2RD (bbch) [19]
BB(6,3) >fω2(10↑↑↑6) 1LE2LD2LC_2RB1RB1RA_2RB1LC0LC_1RB1LD2LD_2RD2LE2LF_1RZ---1LE (bbch)
BB(8,3) >fω+14(fω3(14))>g64 2LH1LE2RA_0LE2LE2RB_1RF1RC2RB_0RC0LD0RH_1RC2LE1LG_0LA0LD1RZ_1LD2RA2LG_2RD1LF1LG (bbch) [20]
BB(9,3) >fω+23(fω+12(fω(14))) 2LI1LE2RA_0LE2LE2RB_1RF1RC2RB_0RC0LD2RA_1RC2LE1LG_0LA0LD1RH_1LD2RA2LG_1RZ2LA2LI_1RD1LI2LH (bbch)
BB(10,3) >fω+42(4) 1LD2RG2LA_2LE2LH2RB_2RE1RC2RB_0RC1RD0LG_0LF1LE1LE_1RG1RZ1LI_0RC1LH2RG_1RC2LH1LA_0LJ2LI---_1LA1RB--- (bbch) [21]
BB(36,3) >fε0(7)
BB(37,3) >fε0(373676378)
4 Symbols: Runtime Champions Reference
BB(1,4) 1 1RZ--------- (bbch)
BB(2,4) 3,932,964 1RB2LA1RA1RA_1LB1LA3RB1RZ (bbch) [1]
BB(3,4) >(2↑155)+14 1RB3LB1RZ2RA_2LC3RB1LC2RA_3RB1LB3LC2RC (bbch) [22]
BB(4,4) >2↑5093>fω(508) 0LB3LB1RZ2RA_1LD3RB1LC2RA_3RB1LB3LC2RC_0RD2RC2LB0RA (bbch) [23]
BB(5,4) >fω2(10↑410↑↑65533) 1LD2RA3RB1LC_1LD2LA3RB---_2RA1LA3RC2LC_2RA---2LD2LE_------1RZ1LD (bbch)
BB(6,4) >fω+1(10↑↑65533)>g64 1LF2RA3RB---_3RD2LB3RB1LC_2RA1LB3RC2LC_1LD2RE0LA1LD_1RZ0LE1LF---_2RA---2LF2LF (bbch)
BB(7,4) >fω+3(21) 3RD1LE2RA1LF_0LE2LE2RB2RD_1RF1RC2RB0LB_0RC0LD3RC2RA_1RC2LE1LG2RF_0LA0LD3LG1RZ_1LD2RA2LG0RB (bbch)
BB(8,4)
BB(9,4)
BB(11,4) >fω×2(2↑116) 1RK3LB1RZ2RA_0LG1LE1LD2RA_3RB1LB3LC2RC_3RE0LI3LC2RC_1RJ3RE3LH2LF_3RF2RF2LE1LF_3LC3LH2LJ2RG_0LE3RH1LI2RG_3RH1LH3LI2RI_0LB0LJ3LJ3RK_2LC0LD2RA3RK (bbch) [24]
BB(12,4) >fω×22(2↑63) 1LH---1LD2RB_2LL3LA1RZ2RB_3RA1LA3LC2RC_3RE---3LC2RC_2LI3RE3LH2LF_3RF2RF2LE1LF_1LL3LH2LJ2RG_2LC3RH1LI2RG_3RH1LH3LI2RI_------3LJ3RK_------2RB3RK_3RB---1LL3LL (bbch)
BB(31,4) >fε0(373676378)
5 Symbols: Runtime Champions Reference
BB(1,5) 1 1RZ------------ (bbch)
BB(2,5) >1010103314360 1RB3LA4RB0RB2LA_1LB2LA3LA1RA1RZ (bbch)
BB(3,5) >fω(2↑155)>fω2(15) 1RB3LB4LC2RA4LB_2LC3RB1LC2RA1RZ_3RB1LB3LC2RC4LC (bbch)
BB(4,5) >fω+1(27041)>g64 1RB3LB4LC2RA4LB_2LC3RB1LC2RA4RD_3RB1LB3LC2RC4LC_2RC2RD1RZ4RB1LC (bbch) [25]
BB(5,5) >fω+1(fω4(6)) 1LB3LB4LC2RA4LB_3LE3RB1LC2RA4RD_3RB1LB3LC2RC4LC_1RZ------4LD4LE_3RB------4LE3LC (bbch) [26]
BB(6,5) >fω+3(11) 2LE3LB4LC2RA4LB_4RA3RB1LC2RA4RD_3RB1LB3LC2RC4LC_1RZ3LF1LA4LD4LE_3RB---0RD4LE3LC_4LC------3LF3LF (bbch) [27]
BB(7,5) >fω+32(10) 2LE3LB4LC2RA4LB_4RA3RB1LC2RA4RD_3RB1LB3LC2RC4LC_1RZ3LF1LG4LD4LE_3RB---1LE4LE3LC_4LC------3LF3LF_3LF------1LG1LG (bbch) [28]
BB(8,5) >fω×2+1(93) 2RG3LB4LC2RA4LB_1RZ---1LD2RA4LD_3RB1LB3LC2RC4LC_3RE---3LC2RC3LC_---3RE4LE4LH4RB_4LE3LG3LB2RF4LG_2LH3RG1LH2RF2RA_3RG1LG3LH2RH4LH (bbch) [29]
BB(19,5) >fε0(1.7⋅10352) 1RB2LA1RA2LB2LA_0LA2RB3RB4RA1LQ_1RZ1RC2LD------_0LK3RD2RD2RD4RD_------0RH1LS0RF_1LG1RF2RF---4RF_4LE1LG2LG---4LG_0LI1RH2RH---4RH_0RK0LJ------4RK_2LE1LJ2LJ---4LJ_4RP---0LE---0LK_2RQ---2LL---4LL_2LN---2RM3RM4RM_4RQ2RQ2LN3LN4LN_4LN---2RO3RO4RO_3LL1LP2LP1LQ4LP_1RC3RR1RM3LP0RO_3LL1RR2RR0RR4RR_1RC1LS2LS1LS4LS (bbch)
BB(94,5) >fψ0(Ω2)(1.7⋅10352)
6 Symbols: Runtime Champions Reference
BB(1,6) 1 1RZ--------------- (bbch)
BB(2,6) >10↑↑10↑↑1010115 1RB3RB5RA1LB5LA2LB_2LA2RA4RB1RZ3LB2LA (bbch) [30]
BB(3,6) >fω3(15) 1RB3LB4LC2RA4LB5LB_2LC3RB1LC2RA5LC1RZ_3RB1LB3LC2RC4LC5LC (bbch)
BB(4,6) >fω+2(29) 5LD3LB5LC2RA4LB4LC_1RZ3RB1LC2RA3RD0LA_3RB1LB3LC2RC4LC1RA_3RB0LA2LC4LD4LC4LD (bbch) [31]
BB(5,6) >fω+3(31) 1LE3LB2LA2RA4LB5RA_1RZ3RB1LC2RA3RD4RA_3RB1LB3LC2RC4LC2LB_3RB0LA5LE4LD4LC4LD_4LC5LC0RE5LE1RE2RE (bbch) [32]
BB(6,6) >fω×2(89) 4LF3LB1RZ2RA4LB---_2LC3RB1LD2RA3LF---_3RB1LB3LC2RC4LC0LE_3RB---3LC2RC---3RE_5RC3RE---4LC------_5RB0LF1RB1LF---5RB (bbch) [33]
BB(7,6) >fω2(110) 5LG3LB---2RA4LB0LC_4LG3RB1LD2RA3LF5RB_3RB1LB3LC2RC4LC1LE_3RB3RE3LC2RC---3RD_5RB3RE0LE4LC3LG5LE_5RB5RB2LB1LF---5LF_5LF---0LG1LG---5LG (bbch) [34]
BB(8,6) >fω2+1(fω(31)) 5LH3LB2LH2RA4LB1RZ_2RC3RB1LD2RA3LF5RB_3RB1LB3LC2RC4LC1LE_3RB3RE3LC2RC---3RD_5RB3RE1LE4LC3LG5LE_5RB5RB---1LF5LF5LF_5LF4RG1LB1LG2LG5LG_0LC---1LH1LH---5RG (bbch) [35]
BB(61,6) >fψ0(Ω2)(1.7⋅10352)
7 Symbols: Runtime Champions Reference
BB(2,7) >10↑↑10↑↑10↑↑155 1RB3RB4LA1LB5LA6LB5RA_2LA6RA4RB1RZ3LB6LA4RB (bbch) [36]
BB(3,7) >fω+1(117)>g64 6LC3LB6RA2RA4LB5LC5LA_1RZ3RB1LC2RA3RB4LC5RA_3RB1LB3LC2RC4LC1RA6LA (bbch) [37]
BB(4,7) >fω+3(34) 5LC3LB6LA2RA4LB2LD3RB_1RZ3RB1LC2RA3RD2LC4LC_3RB1LB3LC2RC4LC1RA5LD_3RB5LD6LC4LD4LC4LD6LC (bbch) [38]
BB(18,7) >fε0(1.7⋅10352) 1RB2LA1RA2LB2LA------_0LA2RB3RB4RA1LP------_0RZ1RC2LD------------_0LJ3RD2RD2RD4RD------_4LE1LE0RG1LR0RF2LE4LE_1LE1RF5RF---6RF------_0LH1RG2RG---4RG------_0RJ0LI------4RJ------_2LE1LI2LI---4LI------_4RO---0LE---0LJ------_2RP---2LK---4LK------_2LM---2RL3RL4RL------_4RP2RP2LM3LM4LM------_4LM---2RN3RN4RN------_3LK1LO2LO1LP4LO------_1RC3RQ1RL3LO0RN------_3LK1RQ2RQ0RQ4RQ------_1RC1LR2LR1LR4LR------ (bbch)
BB(46,7) >fψ0(Ω2)(1.7⋅10352)
BB(134,7) >fψ0(Ωω)(2050)
8 Symbols or more: Runtime Champions Reference
BB(2,8) >10↑↑10↑↑10↑↑10↑↑155 1RB3RB4LA1LB5LA6LB5RA1RZ_2LA6RA4RB7RA3LB6LA4RB4RA (bbch) [39]
BB(17,8) >fε0(1.7⋅10352) 1RB2LA1RA2LB2LA---------_0LA2RB3RB4RA1LO---------_0RZ1RC2LD---------------_0LJ3RD2RD2RD4RD---------_4LE1LE0RG1LQ0RF2LE4LE---_1LE1RF5RF---6RF---------_0LH1RG2RG---4RG---------_0RJ0LI------4RJ---------_2LE1LI2LI---4LI---------_4RN---0LE---0LJ---------_2RO2RO2LK3LK4LK2LK4LK4RO_2LK---5RL3RL6RL---------_4LK---5RM3RM6RM---------_3LK1LN2LN1LO4LN---------_1RC3RP1RL3LN7RM---------_3LK1RP2RP0RP4RP---------_1RC1LQ2LQ1LQ4LQ--------- (bbch)
BB(2,9) >10↑↑10↑↑10↑↑10↑↑10↑↑155 1RB3RB4LA1LB5LA6LB5RA8RA1RZ_2LA6RA4RB7RA3LB6LA4RB4RA4RA (bbch) [40]
BB(42,9) >fψ0(Ω2)(1.7⋅10352)

Maximum Score Function (Σ(n,m))

Maximum amount of non-zero symbols a Turing machine with n states and m symbols can leave on the tape before halting when started on the blank tape.

2 Symbols: Score Champions Reference
Σ(1) 1 1RZ--- (bbch)
Σ(2) 4 1RB1LB_1LA1RZ (bbch)
Σ(3) 6 1RB1RZ_0RC1RB_1LC1LA (bbch) 1RB1RC_1LC1RZ_1RA0LB (bbch) 1RB1LC_1LA1RB_1LB1RZ (bbch) 1RB1RA_1LC1RZ_1RA1LB (bbch) 1RB1LC_1RC1RZ_1LA0LB (bbch)
Σ(4) 13 1RB1LB_1LA0LC_1RZ1LD_1RD0RA (bbch) 1RB0RC_1LA1RA_1RZ1RD_1LD0LB (bbch)
Σ(5) 4098 1RB1LC_1RC1RB_1RD0LE_1LA1LD_1RZ0LA (bbch) 1RB1RA_1LC1LB_1RA1LD_1RA1LE_1RZ0LC (bbch)
Σ(6) > 10 ↑↑ 10 ↑↑ 10 ↑↑ 8.10237 1RB1RA_1RC1RZ_1LD0RF_1RA0LE_0LD1RC_1RA0RE (bbch) [2]
Σ(7) >3↑203>fω(20) 1RB0RG_1RC1RB_0RD1RZ_0LE0LD_0LF1LE_1RA1LF_1LC0RB (bbch) [3]
3 Symbols: Score Champions Reference
Σ(1,3) 1 1RZ------ (bbch)
Σ(2,3) 9 1RB2LB1RZ_2LA2RB1LB (bbch)
Σ(3,3) ≥ 374,676,383 0RB2LA1RA_1LA2RB1RC_1RZ1LB1LC (bbch)
Σ(4,3) >2↑↑↑2↑↑↑2↑↑↑(7.92×1028) 1RB1RD1LC_2LB1RB1LC_1RZ1LA1LD_0RB2RA2RD (bbch) [19]
4 Symbols: Score Champions Reference
Σ(1,4) 1 1RZ--------- (bbch)
Σ(2,4) 2050 1RB2LA1RA1RA_1LB1LA3RB1RZ (bbch)
Σ(3,4) ≥(2↑155)+14 1RB3LB1RZ2RA_2LC3RB1LC2RA_3RB1LB3LC2RC (bbch) [22]
5 Symbols: Score Champions Reference
Σ(1,5) 1 1RZ------------ (bbch)
Σ(2,5) >1010103314360 1RB3LA4RB0RB2LA_1LB2LA3LA1RA1RZ (bbch)
6 Symbols: Score Champions Reference
Σ(1,6) 1 1RZ--------------- (bbch)
Σ(2,6) >10↑↑10↑↑1010115 1RB3RB5RA1LB5LA2LB_2LA2RA4RB1RZ3LB2LA (bbch) [30]

Beeping Busy Beavers

Beeping Busy Beaver (BBB(n,m))

Considering beep states

2 Symbols: Steps taken Champions Reference
BBB(1) 1 [41]
BBB(2) 6 1RB1LB_1LB1LA (bbch) [41]
BBB(3) 55 1RB0LB_1LA0RC_1LC1LA (bbch)
BBB(4) 32,779,478 1RB1LD_1RC1RB_1LC1LA_0RC0RD (bbch) [42]
BBB(5) ≥1014006 1RB1LE_0LC0LB_0LD1LC_1RD1RA_0RC0LA (bbch) [43]
3 Symbols: Steps taken Champions Reference
BBB(1,3)
BBB(2,3) 59 1RB2LB1LA_2LB2RA0RA (bbch) [44]
BBB(3,3) ≥ 10 ↑↑ 6.74 1RB0LB2LA_1LA0RC0LB_2RC2RB0LC (bbch) [45]
4 Symbols: Steps taken Champions Reference
BBB(1,4)
BBB(2,4) ≥205770076433044242247859>2×1023 1RB2LA1RA1LB_0LB2RB3RB1LA (bbch) [46]

Beeping Booping Busy Beaver (BBBB(n,m))

Domain Value Champions Reference
BBBB(1) 2 0RA--- (bbch) (beep: any, boop: A0) [47]
BBBB(2) 18 0RB1LB_1LA1RB (bbch) (beep: A0, boop: A1) [48]
BBBB(3) ≥ 127 1RB1LB_0RC0LA_1LC0LA (bbch) (beep: A0, boop: B1) [49]
BBBB(2,3) ≥ 187 2RB2LA1RA_1LB1LA0RB (bbch) (beep: B0, boop: B2) [49]

Maximum Consecutive Ones Function (Num(n,m))

Domain Number of Ones Champions Reference
num(1) 1 1RZ--- (bbch)
num(2) 4 1RB1LB_1LA1LZ (bbch)
num(3) 6 1RB1LC_1RC1LZ_1LA0LB (bbch)
num(4) 12 1RB0LA_1RC1LB_1LB1RD_1RZ0RA (bbch)
num(5) 165 1RB1LA_1RC1LE_1RD1RE_0LA1RC_1RZ0LB (bbch) 0RB1LD_1LC1RB_1LD1RE_1LA1LE_1LZ0RC (bbch) [50]
num(6) ≥ ≈ 10↑↑15.60465 1RB0LD_1RC0RF_1LC1LA_0LE0RZ_1LF0RB_0RC0RE (bbch)
num(2,3) 6 1RB1LA1LB_0LA2RA1RZ (bbch)
num(3,3) ≥ 12 1RB1RA1RZ_1LC1LC2LA_2RA1LB1LA (bbch)
num(4,3) >10↑44 1RB1RD1LC_2LB1RB1LC_1RZ1LA1LD_0RB2RA2RD (bbch) [19]
num(4,4) >2↑155 1RB3LB1LD2RA_2LC3RB1LC2RA_3RB1LB3LC2RC_1LZ---1LD1LD (bbch)

Maximum Space Function (BBspace(n,m))

Domain Cells visited Champions Reference
BBspace(1,2) 1 1RZ--- (bbch)
BBspace(2,2) 4 1RB1LB_1LA1RZ (bbch) and 1RB0LB_1LA1RZ (bbch)
BBspace(3,2) 7 1RB1RC_1LC1RZ_1RA0LB (bbch) and 1RB0RC_1LC1RZ_1RA0LB (bbch)
BBspace(4,2) 16 1RB0RA_1LC0RD_0LD0LB_1RA1RZ (bbch)
BBspace(5,2) 12289 1RB1LC_1RC1RB_1RD0LE_1LA1LD_1RZ0LA (bbch) [50]
BBspace(1,3) 1 1RZ------ (bbch)
BBspace(2,3) 9 1RB2LB1RZ_2LA2RB1LB (bbch)
BBspace(2,4) 2050 1RB2LA1RA1RA_1LB1LA3RB1RZ (bbch)

Size of the runtime spectrum (R(n,m))

There currently doesn't seem to be any available information about values of this function.

Reversible Turing Machines

Maximum Shifts Function (BBrev(n,m))

Domain Steps Champions Reference
BBrev(1)
BBrev(2) 6 0RB1RZ_1LA1RB (bbch) [51]
BBrev(3) 17 0RB1RZ_0LC1RA_1RB1LC (bbch) [52]
BBrev(4) 48 1RB0LD_0LC0RB_1LA1LD_1LC1RZ (bbch) [53][54]
BBrev(5) 388 1RB0RD_1RC0RB_1RD1RZ_1LE1LA_0LE0LA (bbch) [55][56]
BBrev(6) ≥ 537,556 1RB1LD_1LC1RE_0LD0LC_0RE0RF_0RA1RZ_1RF1RA (bbch) [57]
BBrev(7) >1019 1RB1LD_0LC0LD_1LC1LA_0LA1RE_0RF0RE_0RG1RF_0RB1RZ (bbch)

Maximum Score Function (Σrev(n,m))

Domain Score Champions Reference
Σrev(1)
Σrev(2) ≥ 2 0RB1RZ_1LA1RB (bbch)
Σrev(3) ≥ 4 0RB1RZ_0LC1RA_1RB1LC (bbch)
Σrev(4) ≥ 8 1RB0LA_1LC1RD_1LA0LC_0RB1RZ (bbch) [53]
Σrev(5) ≥ 16 1RB0RD_1RC0RB_1RD1RZ_1LE1LA_0LE0LA (bbch) [56]
Σrev(6) ≥ 1161 1RB1LD_1LC1RE_0LD0LC_0RE0RF_0RA1RZ_1RF1RA (bbch) [57]

Blanking Busy Beaver (BLB(n,m))

2 Symbols: Steps Champions Reference
BLB(1) nonexistent nonexistent
BLB(2) 8 1RB0RA_1LB1LA (bbch) [46]
BLB(3) 34 1RB1LB_1LA1LC_1RC0LC (bbch) [58]
BLB(4) ≥ 32,779,477 1RB1LD_1RC1RB_1LC1LA_0RC0RD (bbch) [59]
BLB(5) > 1014,006 1RB1LE_0LC0LB_0LD1LC_1RD1RA_0RC0LA (bbch) [60]
BLB(6) > 10 ↑↑ 16 1RB0LD_1RC0RF_1LC1LA_0LE1RE_1LF0RB_0RC0RE (bbch)
BLB(7) > 10^183.76332 1RB0RF_1RC1RA_1LD0LA_0RG0RE_0RA1LF_0LE0LC_1RZ0RD (bbch) [61]
3 Symbols: Steps Champions Reference
BLB(1,3) nonexistent nonexistent
BLB(2,3) 77 1RB2LA0RB_1LA0LB1RA (bbch) [58]
BLB(3,3) > 10 ↑↑ 6.54 1RB1RC2RA_0RC2RA0RB_2LC2LB0LA (bbch) [45]
4 Symbols: Steps Champions Reference
BLB(1,4) nonexistent nonexistent
BLB(2,4) ≥ 1,367,361,263,049 1RB2RA1RA2RB_2LB3LA0RB0RA (bbch) [58]
5 Symbols: Steps Champions Reference
BLB(2,5) > 1032 1RB2RB4RA0RB2RA_2LB3LA0RB0RA1RB (bbch)

Busy Cleaner (BB_clean(n,m))

Domain Steps Champions Reference
BBclean(2) ≥ 4
BBclean(3) ≥ 12
BBclean(4) ≥ 34
BBclean(5) ≥ 187

Lazy Beaver

Shifts Function (LB(n,m))

1 State 2 States 3 States 4 States 5 States 6 States
2 Symbols 2 7 22 72 427 8407
3 Symbols 2 23 351 189,270
4 Symbols 2 93 242,789
5 Symbols 2 956
6 Symbols 2 33,851

Period-oriented Busy Beavers

Busy Preperiodic Beaver (BBS(n,m))

Domain Preperiod Champions Reference
BBS(1,2) 0 1RA--- (bbch)
BBS(2,2) ≥ 9 1RB0LB_1LA0RB (bbch) proven winner? [62]
BBS(3,2) 101 1RB1LB_0RC0LA_1LC0LA (bbch) [62]
BBS(4,2) ≥ 119,120,230,102 1RB1LC_0LA1RD_0RB0LC_1LA0RD (bbch)
BBS(5,2) > 1014,006 1RB1LE_0LC0LB_0LD1LC_1RD1RA_0RC0LA (bbch)
BBS(1,3) 0 1RA------ (bbch)
BBS(2,3) ≥ 165 1RB0LA---_1LB2LA0RB (bbch) [62]
BBS(3,3) > 10 ↑↑ 6 1RB0LB2LA_1LA0RC0LB_2RC2RB0LC (bbch)
BBS(4,3) > 10↑44 1RB1RD1LC_2LB1RB1LC_1LB1LA1LD_0RB2RA2RD (bbch)
BBS(1,4) 0 1RA--------- (bbch)
BBS(2,4) ≥ 205,770,076,433,044,242,247,860 1RB2LA1RA1LB_0LB2RB3RB1LA (bbch)

Busy Periodic Beaver (BBP(n,m))

Domain Period Champions Reference
BBP(1,2) 1 1RA--- (bbch)
BBP(2,2) ≥ 9 1RB0RB_1LB1RA (bbch) proven winner?
BBP(3,2) 92 1RB0LA_0RC1LA_1LC0RB (bbch)
BBP(4,2) ≥ 212,081,736 1RB0LA_0RC1RD_1LD0RB_1LA1RB (bbch)
BBP(5,2) ≥ 8,468,569,863 1LC1LE_---1LD_1RD0LD_1LA1RE_0LB0RC (bbch) [63]
BBP(6,2) >2.4154×102695 1RB1LC_1LA1RB_1LD0LA_1RE1RD_---1RF_1LB0RF (bbch), 1RB1LA_1LA1RC_1RD0RB_1LE1LD_---1LF_1RA0LF (bbch) [64]
BBP(1,3) 1 1RA------ (bbch)
BBP(2,3)
BBP(3,3) ≥ 1,195 1RB2RC1LC_0RC0RB1LA_2LA2RC1LB (bbch)
BBP(1,4) 1 1RA--------- (bbch)
BBP(2,4) ≥ 33,209,131 1RB0RA3LB1RB_2LA0LB1RA2RB (bbch)

Instruction-Limited Busy Beaver

Instruction-Limited Classical Busy Beaver Functions

Instruction-Limited Maximum Shifts Function (BBi(n))

Steps Champions Classical Domain Reference
BBi(1) 1 0RH (bbch) 1RH--- (bbch) BB(1)
BBi(2) 3 0RB---_1LA--- (bbch) BB(2) [65]
BBi(3) 5 1RB1LB_1LA--- (bbch) BB(2) [66]
BBi(4) 16 1RB---_0RC---_1LC0LA (bbch) BB(3) [67]
BBi(5) 37 1RB2LB---_2LA2RB1LB (bbch) BB(2,3) [68]
BBi(6) 123 1RB3LA1RA0LA_2LA------3RA (bbch) BB(2,4) [69]
BBi(7) 3,932,963 1RB2LA1RA1RA_1LB1LA3RB--- (bbch) 1RB2LA1RA_1LC1LA2RB_---1LA--- (bbch) BB(2,4) [70]
BBi(8) >6.889×101565 1RB1LA------_1RC3LB1RB---_2LA2LC---0LC (bbch) BB(3,4) [71]
BBi(9) >1010103314360 1RB3LA4RB0RB2LA_1LB2LA3LA1RA--- (bbch) BB(2,5)
BBi(10)
BBi(11) >2↑155 1RB3LB---2RA_2LC3RB1LC2RA_3RB1LB3LC2RC (bbch) BB(3,4)
BBi(12) >2↑183 0RD3LB---2RA_2LC3RB1LC2RA_3RB1LB3LC2RC_1RB--------- (bbch) BB(4,4) [72]
BBi(13) >2↑984>fω(97) 1LD3LB---2RA_2LC3RB1LC2RA_3RB1LB3LC2RC_0LB---2LB--- (bbch) BB(4,4) [72]
BBi(14) >fω(2↑155) 1RB3LB4LC2RA4LB_2LC3RB1LC2RA---_3RB1LB3LC2RC4LC (bbch) BB(3,5)
BBi(15) >fω3(12) 1RB0RA_1LC1LF_1RD0LB_1RA1LE_1LH0LC_1RG1LD_0RG0RF_1RG--- (bbch) BB(8) [4]
BBi(16)
BBi(17) >fω11(15) 1RB3LB4LC2RA4LB_2LC3RB1LC2RA4RD_3RB1LB3LC2RC4LC_3RC------3RA--- (bbch) BB(4,5) [73]
BBi(18) >fω+1(2611)>g64 1RB3LB4LC2RA4LB_2LC3RB1LC2RA4RD_3RB1LB3LC2RC4LC_1LC3LC---1RD--- (bbch) BB(4,5) [73]
BBi(19) >fω+12(2↑64) 5LD3LB---2RA4LB---_---3RB1LC2RA3RD2LC_3RB1LB3LC2RC4LC---_3RB---5LD4LD4LC4LD (bbch) BB(4,6)
BBi(20) >fω+14(fω2(2↑64)) 5LD3LB---2RA4LB2RB_---3RB1LC2RA3RD3LB_3RB1LB3LC2RC4LC---_3RB---5LD4LD4LC4LD (bbch) BB(4,6)
BBi(21) >fω+2(fω+12(2↑64)) 2LF3LB---2RA4LB---_---3RB1LC2RA3RD---_3RB1LB3LC2RC4LC---_3RB---5LE4LD4LC4LD_4LC------5LE------_2LE--------------- (bbch) BB(6,6)
BBi(22) >fω+22(fω+12(2↑64)) 1RF3LB---2RA4LB---_---3RB1LC2RA3RD---_3RB1LB3LC2RC4LC---_3RB---5LE4LD4LC4LD_4LC2LF---5LE------_2LE--------------- (bbch) BB(6,6)
BBi(23) >fω+3(8) 1LF3LB---2RA4LB---_---3RB1LC2RA3RD---_3RB1LB3LC2RC4LC---_3RB2LF5LE4LD4LC4LD_4LC------5LE------_4LE------2LF------ (bbch) BB(6,6)
BBi(24)
BBi(25) >fω+5(28) 3LF3LB---2RA4LB---_2LF3RB1LD2RA3LF---_3RB1LB3LC2RC4LC0LE_3RB---3LC2RC---3RE_5RC3RE---4LC------_5RB---2LC1LF------ (bbch) BB(6,6)
BBi(26) >fω×2(36) 5RB3LB---2RA4LB---_2LC3RB1LD2RA3LF---_3RB1LB3LC2RC4LC0LE_3RB3RD3LC2RC---3RE_5RC3RE1RB4LC------_5RB------1LF------ (bbch) BB(6,6) [74]
BBi(27) >fω×2(89) 4LF3LB---2RA4LB---_2LC3RB1LD2RA3LF---_3RB1LB3LC2RC4LC0LE_3RB---3LC2RC---3RE_5RC3RE---4LC------_5RB0LF1RB1LF---5RB (bbch) BB(6,6) [33]
BBi(28)
BBi(29) >fω×2(fω+1(fω(30))) 5LF3LB1LG2RA4LB---_---3RB1LD2RA3LF3LG_3RB1LB3LC2RC4LC0LE_3RB---3LC2RC---3RE_5RC3RE---4LC------_5RB---2LB1LF------_------1LG3LG---0LE (bbch) BB(7,6)
BBi(30) >fω×23(fω+2(28)) 5LF3LB1LG2RA4LB---_---3RB1LD2RA3LF3LF_3RB1LB3LC2RC4LC0LE_3RB---3LC2RC---3RE_5RC3RE---4LC------_5RB---2LF1LF---5RA_------1LG3LG---0LE (bbch) BB(7,6)
BBi(31) >fω×2+1(19) 5LF3LB1LG2RA4LB---_2LC3RB1LD2RA3LF2LB_3RB1LB3LC2RC4LC0LE_3RB---3LC2RC---3RE_5RC3RE2LE4LC------_5RB---2LE1LF------_------1LG3LG---0LE (bbch) BB(7,6)
BBi(32) >fω×2+1(130) 5LF3LB1LG2RA4LB---_2LC3RB1LD2RA3LF2LB_3RB1LB3LC2RC4LC0LE_3RB---3LC2RC---3RE_5RC3RE2LF4LC---0RB_5RB---2LE1LF------_------1LG3LG---0LE (bbch) BB(7,6)
BBi(33)
BBi(34) >fω2(5) 2LG3LB---2RA4LB---_4LG3RB1LD2RA3LF5RB_3RB1LB3LC2RC4LC1LE_3RB3RE3LC2RC---3RD_5RB3RE---4LC3LG5LE_5RB5RB---1LF---5LF_5LF---1LC1LG---5LG (bbch) BB(7,6)
BBi(35) >fω2(28) 2LF3LB---2RA4LB3LD_3LA3RB1LD2RA3LF5RB_3RB1LB3LC2RC4LC1LE_3RB3RE3LC2RC---3RD_5RB3RE---4LC3LG5LE_5RB5RB0LF1LF---5LF_5LF------1LG---5LG (bbch) BB(7,6) [75]
BBi(36) >fω2(63) 2LE3LB---2RA4LB2LD_0LA3RB1LD2RA3LF5RB_3RB1LB3LC2RC4LC1LE_3RB3RE3LC2RC---3RD_5RB3RE0LG4LC3LG5LE_5RB5RB---1LF---5LF_5LF---3RC1LG---5LG (bbch) BB(7,6) [76]
BBi(37) >fω2(110) 5LG3LB---2RA4LB0LC_4LG3RB1LD2RA3LF5RB_3RB1LB3LC2RC4LC1LE_3RB3RE3LC2RC---3RD_5RB3RE0LE4LC3LG5LE_5RB5RB2LB1LF---5LF_5LF---0LG1LG---5LG (bbch) BB(7,6) [34]
...
BBi(41) >fω22(4↑↑341) 0LI0LF_0RJ1RG_0RD1LC_1RH1RE_1LO0RH_1LA1LF_0LC1LA_1RB1RH_1RD0LF_1LP0RK_0LM1LL_0LL1LM_1LE1LN_0RQ0LM_0RP1LO_1LR0RH_1LF1RQ_---0LS_1LH0LT_1LH1LU_0LE1LR (bbch) BB(21) [77]
BBi(42) fω2+1(29) 5LH3LB2LH2RA4LB---_---3RB1LD2RA3LF5RB_3RB1LB3LC2RC4LC1LE_3RB3RE3LC2RC---3RD_5RB3RE1LE4LC3LG5LE_5RB5RB---1LF5LF5LF_5LF4RG1LB1LG2LG5LG_3RC---1LH1LH---5RG (bbch) BB(8,6)
BBi(43) >fω2+1(fω(31)) 5LH3LB2LH2RA4LB1RZ_2RC3RB1LD2RA3LF5RB_3RB1LB3LC2RC4LC1LE_3RB3RE3LC2RC---3RD_5RB3RE1LE4LC3LG5LE_5RB5RB---1LF5LF5LF_5LF4RG1LB1LG2LG5LG_0LC---1LH1LH---5RG (bbch) BB(8,6) [35]
...
BBi(57) >fωω(3) [5] BB(29) [14]
BBi(61) >fω↑↑4(3) [6] BB(31) [15]
BBi(65) >fω↑↑6(3) [7] BB(33) [16]
BBi(78) >fε0(1.7⋅10352)
BB(19,5) machine code
1RB2LA1RA2LB2LA_0LA2RB3RB4RA1LQ_---1RC2LD------_0LK3RD2RD2RD4RD_------0RH1LS0RF_1LG1RF2RF---4RF_4LE1LG2LG---4LG_0LI1RH2RH---4RH_0RK0LJ------4RK_2LE1LJ2LJ---4LJ_4RP---0LE---0LK_2RQ---2LL---4LL_2LN---2RM3RM4RM_4RQ2RQ2LN3LN4LN_4LN---2RO3RO4RO_3LL1LP2LP1LQ4LP_1RC3RR1RM3LP0RO_3LL1RR2RR0RR4RR_1RC1LS2LS1LS4LS (bbch)
BB(18,7) machine code
1RB2LA1RA2LB2LA------_0LA2RB3RB4RA1LP------_---1RC2LD------------_0LJ3RD2RD2RD4RD------_4LE1LE0RG1LR0RF2LE4LE_1LE1RF5RF---6RF------_0LH1RG2RG---4RG------_0RJ0LI------4RJ------_2LE1LI2LI---4LI------_4RO---0LE---0LJ------_2RP---2LK---4LK------_2LM---2RL3RL4RL------_4RP2RP2LM3LM4LM------_4LM---2RN3RN4RN------_3LK1LO2LO1LP4LO------_1RC3RQ1RL3LO0RN------_3LK1RQ2RQ0RQ4RQ------_1RC1LR2LR1LR4LR------ (bbch)
BB(17,8) machine code
1RB2LA1RA2LB2LA---------_0LA2RB3RB4RA1LO---------_---1RC2LD---------------_0LJ3RD2RD2RD4RD---------_4LE1LE0RG1LQ0RF2LE4LE---_1LE1RF5RF---6RF---------_0LH1RG2RG---4RG---------_0RJ0LI------4RJ---------_2LE1LI2LI---4LI---------_4RN---0LE---0LJ---------_2RO2RO2LK3LK4LK2LK4LK4RO_2LK---5RL3RL6RL---------_4LK---5RM3RM6RM---------_3LK1LN2LN1LO4LN---------_1RC3RP1RL3LN7RM---------_3LK1RP2RP0RP4RP---------_1RC1LQ2LQ1LQ4LQ--------- (bbch)
BB(19,5), BB(18,7), BB(17,8)
BBi(94) >fε1(3) [8] BB(48) [78]
BBi(237) >fψ0(Ω2)(1.7⋅10352) BB(42,9)
BBi(299) >flim(BMS)(10↑↑15) too large to show BB(150) [18]
BBi(2029) > D5(99) = Loader's Number BB(1015)

Instruction-Limited Maximum Score Function (Σi(n))

Score Champions Classical Domain Reference
Σi(1) 1 1RH--- (bbch) BB(1)
Σi(2) 2 1RB---_1LA--- (bbch) BB(2) [65]
Σi(3) 4 1RB1LB_1LA--- (bbch) BB(2) [66]
Σi(4) 5 1RB0LB---_1LA2RA--- (bbch) BB(2,3) [67]
Σi(5) 9 1RB2LB---_2LA2RB1LB (bbch) BB(2,3) [68]
Σi(6) 14 1RB3LA1RA0LA_2LA------3RA (bbch) BB(2,4) [69]
Σi(7) 2050 1RB2LA1RA1RA_1LB1LA3RB--- (bbch) 1RB2LA1RA_1LC1LA2RB_---1LA--- (bbch) BB(2,4) [70]
Σi(8) >1.355×10783 1RB1LA------_1RC3LB1RB---_2LA2LC---0LC (bbch) BB(3,4) [79]
Σi(9) >1010103314360 1RB3LA4RB0RB2LA_1LB2LA3LA1RA--- (bbch) BB(2,5)

Instruction-Limited Blanking Busy Beaver (BLBi(n))

Steps Champions
BLBi(1) nonexistent nonexistent
BLBi(2) nonexistent nonexistent
BLBi(3) 4 1RB0RA_1LA--- (bbch)
BLBi(4) 12 1RB---_1RC---_1LC0RC (bbch)
BLBi(5) 30 1RB------_1RC------_2LC2RC0RC (bbch)
BLBi(6) 77 1RB2LA0RB_1LA0LB1RA (bbch)
BLBi(7) 808 1RB------_1RC------_0RD2LC---_1LD2RD0RC (bbch)
BLBi(8) ≥ 1,367,361,263,049 1RB2RA1RA2RB_2LB3LA0RB0RA (bbch)
BLBi(9) > 1042,745 1RB2RB1LA_2LC0LB2LB_2RC2RA0LC (bbch)

Instruction-Limited Greedy Busy Beaver (gBBi(n))

Steps Champions
gBBi(1) 1
gBBi(2) 3
gBBi(3) 5
gBBi(4) 13
gBBi(5) 19
gBBi(6) 25
gBBi(7) 41
gBBi(8) 55
gBBi(9) 238
gBBi(10) 941
gBBi(11) 1341
gBBi(12) 10465
gBBi(13) 10675
gBBi(14) ≥ 9,874,580 0RB6RB1LB---3LA1RB7RB2LB_1LA2RB3LA4RB5RB1LB5LA--- (bbch)

Program-Limited Busy Beaver

Busy Beaver for Lambda Calculus

Regular Busy Beaver for Lambda Calculus (BBλ(n))

For n = 0,1,2,3,5 BBλ(n) is undefined, while for the rest of 20≥n BBλ(n) = n.

BBλ(n) Champions
BBλ(4) 4 λ1
BBλ(6) 6 λλ1
BBλ(7) 7 λλ2
BBλ(8) 8 λλλ1
BBλ(9) 9 λλλ2
BBλ(10) 10 λλλλ1
BBλ(11) 11 λλλλ2
BBλ(12) 12 λλλλλ1
BBλ(13) 13 λλλλλ2
BBλ(14) 14 λλλλλλ1
BBλ(15) 15 λλλλλλ2
BBλ(16) 16 λλλλλλλ1
BBλ(17) 17 λλλλλλλ2
BBλ(18) 18 λλλλλλλλ1
BBλ(19) 19 λλλλλλλλ2
BBλ(20) 20 λλλλλλλλλ1
BBλ(21) 22 λ(1(λ2))(1(λ2))
BBλ(22) 24 λ(11)(11)(11)
BBλ(23) 26 λ(1(λλ2))(1(λλ2))
BBλ(24) 30 λ(1(λ1))(1(λ1))(1(λ1))
BBλ(25) 42 λ1(λ1(21))(1(1(λ1(21))))
BBλ(26) 52 λλ2(λλ2(12))(1(2(λλ2(12))))
BBλ(27) 44 λλ1(λ1(21))(1(1(λ1(21))))
BBλ(28) 58 λ1(λλ1(3(λ2)))(1(λ2(λλ1(4(λ2)))))
BBλ(29) 223 λ(λ11)(λ1(1(21)))
BBλ(30) 160 (λ111)(λλ2(12))
BBλ(31) 267 (λ11)(λλ2(2(12)))
BBλ(32) 298 λ(λ11)(λ1(1(2(λ2))))
BBλ(33) 1812 λ(λ11)(λ1(1(1(21))))
BBλ(34) 327,686 (λ1111)(λλ2(21))
BBλ(35) 5×333+6=38127987424941>3.8×1013 (λ111)(λλ2(2(21)))
BBλ(36) 5×2223+6>5.7×1077 (λ11)(λ1(1(λλ2(21))))
BBλ(37) BBλ(35)+2=5×333+8=38127987424943>3.8×1013 λ(λ111)(λλ2(2(21)))
BBλ(38) 5×22222+6>1019729 (λ11111)(λλ2(21))
BBλ(39) 5×3333+6>103638334640024 (λ1111)(λλ2(2(21)))
BBλ(40) ≈(2↑↑)1533>10↑↑↑16 (λ111)(λ1(λλ2(21))1)
BBλ(41) 5×3385+6>101.7×1040 (λ1(λ11)1)(λλ2(2(21)))
BBλ(42) ≥BBλ(40)+2>(2↑↑)1533>10↑↑↑16 λ(λ111)(λ1(λλ2(21))1)
BBλ(43) >2↑↑↑2↑↑↑(2↑↑82) (λ11)(λ1(λ1(λλ2(21))2))
BBλ(44) >10↑↑↑10↑↑↑16 (λ1111)(λ1(λλ2(21))1)
BBλ(45) ≥BBλ(43)+2>2↑↑↑2↑↑↑(2↑↑82) λ(λ11)(λ1(λ1(λλ2(21))2))
BBλ(46) ≥BBλ(44)+2>10↑↑↑10↑↑↑16 λ(λ1111)(λ1(λλ2(21))1)
BBλ(47) >fω(f5(2)) (λ111)(λλ1(12)(λλ2(21)))
BBλ(48) >10↑↑↑10↑↑↑10↑↑↑16 (λ11111)(λ1(λλ2(21))1)
BBλ(49) >fω+1(2↑↑62)>Graham's Number (λ11)(λ1(1(λλ12(λλ2(21)))))
BBλ(61) >fω2↑↑18−1(2) (λ111)(λ1(1(λλλ132(λλ2(21)))))
BBλ(70) >fωω2(fωω(fωω(3))) (λ11(λ1(λλλ1325)2)1)(λλ2(21))
BBλ(74) >fωω2+1(7) (λ111(λ1(λλλ1325)2)1)(λλ2(21))
BBλ(76) >fωω3(2) (λ11(λλλλ14321)1111)(λλ2(21))
BBλ(77) >fωω2(3) (λ1(λλλλ14321)1111)(λλ2(2(21)))
BBλ(80) >fωω14(2) (λ111(λλλλ14321)1111)(λλ2(21))
BBλ(82) >fωωω(2↑↑↑↑18) (λ1(λ1(λλλλ14321)1111)1)(λλ2(21))
BBλ(90) >fζ0(15) (λ11(λλλλ1444321)1111)(λλ2(21))
BBλ(94) >fψ(Ωω)(12) (λ111(λλλλ1444321)1111)(λλ2(21))
BBλ(95) >fψ(Ωω)(23) (λ11(λλλλ1444321)1111)(λλ2(2(21)))
BBλ(96) >fψ(Ωω)(fωω2(2)) (λ1(λ1(λλλλ1444321)1111)1)(λλ2(21))
BBλ(100) >fψ(Ωω)+1(4) (λ11(λ1(λλλλ1444321)1111)1)(λλ2(21))
BBλ(201) >q(5) (q is only proven to exceed all functions provably recursive in PA; the true value is likely much larger based on informal analysis) too large to show
BBλ(331) >flim⁡(BMS⁡)3(5) too large to show
BBλ(1797) >D5(99) (Loader's number) too large to show

Oracle Busy Beaver for Lambda Calculus (BBλ1(n))

Note that f(n)=6+5×BBλ(n).

BBλ1(n) Champions
BBλ1(1) 0
BBλ1(2) 2 1
BBλ1(3) 0
BBλ1(4) 4 λ1
BBλ1(5) 5 λ2
BBλ1(6) 6 λλ1
BBλ1(7) 7 λλ2
BBλ1(8) 26 1(λ1)
BBλ1(9) 9 λλλ2
BBλ1(10) 36 1(λλ1)
BBλ1(11) 41 1(λλ2)
BBλ1(12) 266 1(1(λ1))
BBλ1(13) 51 1(λλ2)
BBλ1(14) f(36)=25×2223+36>2.85×1078 1(1(λλ1))
BBλ1(15) f(41)=25×3385+36>101.7×1040 1(1(λλ2))
BBλ1(16) f(266) 1(1(1(λ1)))
BBλ1(17) f(51) 1(1(λλλ2))
BBλ1(18) f4(4)=f(f(266)) 1(λ1)1(λ1)
BBλ1(19) f3(7)=f(f(41)) 1(1(1(λλ2)))
BBλ1(20) f6(4)=f4(266) 1(λλ1)1(λ1)
BBλ1(21) f7(4)=f5(266) 1(λλ2)1(λ1)
BBλ1(22) f26(4)=f24(266) 1(1(λ1))1(λ1)
BBλ1(28) ≥fBBλ(f3(4))(4) 1(λ1)1(λ1)1(λ1)
BBλ1(29) ≥fBBλ(fBBλ(f4(4))+4(4))+BBλ(f4(4))+5(4) 1(λ1)(λ121)(λ1)

Busy Beaver for De Bruijn Lambda Calculus (De Bruijn index)

n Value Champion
7 ≥ 7 \1 1 1 1 1 1
8 ≥ 16 (\1 1) (\\2 (1 2))
9 ≥ 68 (\1 1) (\\2 (2 (1 2)))
10 >7.625×1012 (\1 1 1) (\\2 (2 (2 1)))
11 >107.625×1012 (\1 1 1 1) (\\2 (2 (2 1)))
12 >10↑316 (\1 1 1) (\1 (\\2 (2 1)) 1)
13 >10↑310↑310↑26 (\1 1) (\1 (\1 (\\2 (2 1)) 2))
14 >fω(f5(2)) (\1 1 1) (\\1 (1 2) (\\2 (2 1)))
15 >fω+1(101019,727) (\1 1) (\1 (1 (\\1 2 (\\2 (2 1)))))
18 >fωω(2↑↑18) (\1 1 1) (\1 (1 (\\\1 3 2 (\\2 (2 1)))))
19 >fωω2(fωω2(3)) (\1 1 (\1 (\\1 3 2 5) 2) 1) (\2 (2 1)))
20 >fωω2+1(7) (\1 1 1 (\1 (\\1 3 2 5) 2) 1) (\2 (2 1)))
21 >fωω2+ω+2(2) (\1 1 (\\\\1 4 3 2 1) 1 1 1 1) (\\2 (2 1))
22 >fωω14(2) (\1 1 1 (\\1 4 3 2 1) 1 1 1 1) (\2 (2 1))
23 >fζ0(15) (\1 1 (\\\\1 4 4 4 3 2 1) 1 1 1 1) (\\2 (2 1))
24 >fψ(Ωω)(12) (\1 1 1 (\\\\1 4 4 4 3 2 1) 1 1 1 1) (\\2 (2 1))
25 >fψ(Ωω)(fωω+2(2)) (\1 (\1 (\\\\1 4 4 4 3 2 1) 1 1 1 1) 1) (\\2 (2 1))
26 >fψ(Ωω+1)(4) (\1 1 (\1 (\\\\1 4 4 4 3 2 1) 1 1 1 1) 1) (\\2 (2 1))

Busy Beaver for SKI calculus

Busy Beaver for SKI calculus

Ξ₀(n) Champion
Ξ₀(1) 1 S
Ξ₀(2) 2 SS
Ξ₀(3) 3 SSS
Ξ₀(4) 4 SSSS
Ξ₀(5) 6 SSS(SS)
Ξ₀(6) 17 SSS(SI)S
Ξ₀(7) ≥ 41 SSS(S(SS))S
Ξ₀(8) ≥ 80 SSK(S(SS)S)S
Ξ₀(9) ≥ 1561 S(SI)(SS)(SS)SS
Ξ₀(10) ≥ 1562 S(S(SI)(SS)(SS)SS)
Ξ₀(11) ≥ 1563 SS(S(SI)(SS)(SS)SS)
Ξ₀(12) ≥ 2↑2↑513*8-2 S(SI)(SSK)(S(S(KS)K)I)
Ξ₀(13) > 2↑↑2↑↑2↑258 SI(SI)(SSK)(S(S(KS)K)I)
Ξ₀(14) > 2↑↑2↑↑2↑258 SI(SI)(SSK)(S(S(KS)K)I)S
Ξ₀(15) > 2↑↑2↑↑2↑↑34 S(S(SI)I(SSK))I(S(S(KS)K)I)
Ξ₀(16) > 2↑↑↑19 S(S(SI))I(S(SSK)(K(S(S(KS)K)I)))
Ξ₀(17) > 2↑↑↑↑2↑↑2↑↑258 S(SS(SSS)I)(SSK)(S(S(KS)K)I)
Ξ₀(18) > 2↑↑↑↑2↑↑2↑↑258 S(SS(SSS)I)(SSK)(S(S(KS)K)I)S
Ξ₀(19) > 2↑↑↑↑2↑↑↑17 SSI(SSK(S(S(KS)K)I))(S(K(S(SSK)))K)
Ξ₀(20) > fω+1(2↑↑7/2-1) > Graham's Number S(S(S(SI)))I(S(K(S(SS(K(K(S(S(KS)K)I))))))K)
Ξ₀(27) > fω+2(2↑2↑21) SI(SI(SI(S(S(K(SS(KI))))I)))(S(K(S(SSK)))K)(S(S(KS)K)I)
Ξ₀(28) > fω+2(2↑2↑21) S(SI(SI(SI(S(S(K(SS(KI))))I)))(S(K(S(SSK)))K)(S(S(KS)K)I))
Ξ₀(29) > fω+3(2↑2↑21) SI(SI(SI(SI(S(S(K(SS(KI))))I))))(S(K(S(SSK)))K)(S(S(KS)K)I)
Ξ₀(30) > fω+3(2↑2↑21) S(SI(SI(SI(SI(S(S(K(SS(KI))))I))))(S(K(S(SSK)))K)(S(S(KS)K)I))
Ξ₀(31) > fω+4(2↑2↑21) SI(SI(SI(SI(SI(S(S(K(SS(KI))))I)))))(S(K(S(SSK)))K)(S(S(KS)K)I)
Ξ₀(32) > fω+4(2↑2↑21) S(SI(SI(SI(SI(SI(S(S(K(SS(KI))))I)))))(S(K(S(SSK)))K)(S(S(KS)K)I))

Busy Beaver for SK calculus

Ξ₀SK(n) Champion
Ξ₀SK(n)(1) 1 S
Ξ₀SK(n)(2) 2 SS
Ξ₀SK(n)(3) 3 SSS
Ξ₀SK(n)(4) 4 SSSS
Ξ₀SK(n)(5) 6 SSS(SS)
Ξ₀SK(n)(6) 10 SSS(SS)S
Ξ₀SK(n)(7) 41 SSS(S(SS))S
Ξ₀SK(n)(8) ≥ 80 SSK(S(SS)S)S
Ξ₀SK(n)(9) ≥ 169 S(SS)(SS)(SS)SS
Ξ₀SK(n)(10) ≥ 1561 SS(SS)(SSS)SSS
Ξ₀SK(n)(11) ≥ 1562 S(SS(SS)(SSS)SSS)
Ξ₀SK(n)(12) ≥ 1563 S(S(SS(SS)(SSS)SSS))
Ξ₀SK(n)(13) ≥ 7811 S(SS)(SS)(SS(SS(SSS)))S
Ξ₀SK(n)(14) ≥ 2↑2097156*13-2 SSS(SSK)(SS(SK)(S(KS)K))
Ξ₀SK(n)(15) ≥ 2↑2↑2097156*3-2 SSS(SSK)(SS(SK)(S(KS)K))S
Ξ₀SK(n)(16) > 2↑2↑2↑8193 S(SS(SS))(SSK)(SS(SK)(S(KS)K))
Ξ₀SK(n)(17) > 2↑↑2↑↑2↑258 SSS(S(SK))(SSK)(SS(SK)(S(KS)K))
Ξ₀SK(n)(22) > 2↑↑↑19 S(S(S(S(SK))))(S(SK))(S(SSK)(K(SS(SK)(S(KS)K)))
Ξ₀SK(n)(23) > 2↑↑↑↑2↑↑↑17 SS(S(SK))(SSK(SS(SK)(S(KS)K)))(S(K(S(SSK)))K)
Ξ₀SK(n)(24) > 2↑↑↑↑2↑↑↑19 S(SS(S(SK))(SSK(SS(SK)(S(KS)K)))(S(K(S(SSK)))K))
Ξ₀SK(n)(25) > 3↑73 SS(S(SK))(SSK(SS(SS(SK))(S(KS)K)))(S(K(S(SSK)))K)
Ξ₀SK(n)(26) > fω+1(2↑↑7/2-1) > Graham's number S(S(S(S(SKS))))(SKS)(S(K(S(SS(K(K(SS(SK)(S(KS)K)))))))K)

Busy Beaver for BCKW calculus

Ξ₀BCKW(n) Champion
Ξ₀BCKW(1) 1 B
Ξ₀BCKW(2) 2 BB
Ξ₀BCKW(3) 3 BBB
Ξ₀BCKW(4) 11 WW(WB)
Ξ₀BCKW(5) 47 W(WW)(WB)
Ξ₀BCKW(6) ≥ 2↑256*6-1 WW(WC(WB))
Ξ₀BCKW(7) > 2↑↑↑17 WW(C(WC)(WB))
Ξ₀BCKW(8) > 2↑↑↑2↑↑↑17 W(WW)(C(WC)(WB))
Ξ₀BCKW(9) > 2↑52↑↑↑↑2↑↑↑17 WW(WB(C(WC))(WB))
Ξ₀BCKW(10) > fω+1(2↑↑6/2-1) WW(C(WB)(C(CC(WB))))
Ξ₀BCKW(15) > fω2^^18-1(2) WW(C(WB)(B(BC(CC(WB)))(C(BC))))

Brainfuck

BB_brainf(n) Champion
BB_brainf(1) 1 +
BB_brainf(2) 2 ++
BB_brainf(3) 3 +++
BB_brainf(4) 4 ++++
BB_brainf(5) 5 +++++
BB_brainf(6) ≥ 6 ++++++
BB_brainf(7) ≥ 7 +++++++
BB_brainf(8) ≥ 8 ++++++++
BB_brainf(9) ≥ 9 +++++++++
BB_brainf(10) ≥ 10 ++++++++++
BB_brainf(11) ≥ 11 +++++++++++
BB_brainf(12) ≥ 12 ++++++++++++
BB_brainf(13) ≥ 16 ++++[->++++<]
BB_brainf(14) ≥ 20 +++++[->++++<]
BB_brainf(15) ≥ 25 +++++[->+++++<]
BB_brainf(16) ≥ 30 ++++++[->+++++<]
BB_brainf(17) ≥ 36 ++++++[->++++++<]
BB_brainf(18) ≥ 42 +++++++[->++++++<]
BB_brainf(19) ≥ 49 +++++++[->+++++++<]
BB_brainf(20) ≥ 56 ++++++++[->+++++++<]
BB_brainf(21) ≥ 64 ++++++++[->++++++++<]
BB_brainf(22) ≥ 72 +++++++++[->++++++++<]
BB_brainf(23) ≥ 81 +++++++++[->+++++++++<]
BB_brainf(24) ≥ 90 +++++++++[->++++++++++<]
BB_brainf(25) ≥ 340 ++++[>+[->++<]>[-<++>]<<]
BB_brainf(26) ≥ 1364 +++++[>+[->++<]>[-<++>]<<]

Boolfuck

BB_boolf(n) Champion
BB_boolf(1) 1 *
BB_boolf(2) 1 *>
BB_boolf(3) 2 *>*
BB_boolf(4) 2 *>*>
BB_boolf(5) 3 *>*>*
BB_boolf(6) 3 *>*>*>
BB_boolf(7) 4 *>*>*>*

CounterScript

Macros for compression:

Macro Definition Size Function
Constant Addition A+=n; increment A by n n A++; repeated n times
Transfer A>>B*n; increment B by A*n then set A to 0 n+2 while A {A--; (B++; repeated n times)}
BBCS(n) Champion
BBCS(1) 1 A++;
BBCS(2) 2 A++; A++;
BBCS(3) 3 A++; A++; A++;
BBCS(4) 4 A++; A++; A++; A++;
BBCS(5) 5 A++; A++; A++; A++; A++;
BBCS(6) 6 A++; A++; A++; A++; A++; A++;
BBCS(7) 7 A++; A++; A++; A++; A++; A++; A++;
BBCS(8) 9 A++; A++; A++; while A {A--; B++; B++; B++;}
BBCS(9) 12 A++; A++; A++; A++; while A {A--; B++; B++; B++;}
BBCS(10) 16 A++; A++; A++; A++; while A {A--; B++; B++; B++; B++;}
BBCS(11) 20 A++; A++; A++; A++; A++; while A {A--; B++; B++; B++; B++;}
BBCS(12) ≥ 25 A++; A++; A++; A++; A++; while A {A--; B++; B++; B++; B++; B++;}
BBCS(13) ≥ 42 A++; while A {A++; while B {A--; B--; C++; C++;} C>>B*2; C++;}
BBCS(14) ≥ 129 A++; while A {A++; while B {A--; B--; C++; C++;} C>>B*3; C++;}
BBCS(15) ≥ 340 A++; A++; A++; A++; while A {A--; B++; while B {B--; C++; C++;} while C {C--; B++; B++;}}
BBCS(16) ≥ 1,554 A++; A++; A++; A++; while A {A--; B++; while B {B--; C++; C++; C++;} while C {C--; B++; B++;}}
BBCS(17) ≥ 9,330 A++; A++; A++; A++; A++; while A {A--; B++; while B {B--; C++; C++; C++;} while C {C--; B++; B++;}}
BBCS(18) ≥ 66,429 A++; A++; A++; A++; A++; while A {A--; B++; while B {B--; C++; C++; C++;} while C {C--; B++; B++; B++;}}
BBCS(19) ≥ (3^122 - 3)/2 A++; while A {A++; while B {A--; B--; C++;} while C {B++; C--; B>>D*3; D>>B;} C++;}
BBCS(20) ≥ 2^65536 - 2 A+=4; while A {A--; B++; while B {B--; C++; C>>D*2; D>>C;} C>>B;}
BBCS(21) ≥ 2^2^65536 - 2 A+=5; while A {A--; B++; while B {B--; C++; C>>D*2; D>>C;} C>>B;}
BBCS(22) ≥ 2^^7 - 2 A+=6; while A {A--; B++; while B {B--; C++; C>>D*2; D>>C;} C>>B;}
BBCS(23) ≥ 2^^8 - 2 A+=7; while A {A--; B++; while B {B--; C++; C>>D*2; D>>C;} C>>B;}
BBCS(24) ≥ 2^^65536 - 2 A++; while A {A++; while B {A--; B--; C++;} while C {B++; C--; while B {B--; D++; D>>E*2; E>>D;} D>>B;} C++;}
BBCS(25) > 2^^2^^6 A++; while A {A++; while B {A--; B--; C+=2;} while C {B++; C--; while B {B--; D++; D>>E*2; E>>D;} D>>B;} C++;}
BBCS(26) ≥ 2^^2^^65536 - 2 A++; A++; A++; A++; while A {A--; B++; while B {B--; C++; while C {C--; D++; while D {D--; E++; E++;} while E {E--; D++;}} while D {D--; C++;}} while C {C--; B++;}}
BBCS(64) > Graham's number too large to show
BBCS(85) > q(5) too large to show, see Discord

Fractran (BBf(n))

n BBf(n) Example Champion Vector Representation
BBf(2) 1 [1/2] [−1]
BBf(3) 1 [3/2] [−11]
BBf(4) 1 [9/2] [−12]
BBf(5) 2 [3/2, 1/3] [−110−1]
BBf(6) 3 [9/2, 1/3] [−120−1]
BBf(7) 4 [27/2, 1/3] [−130−1]
BBf(8) 5 [81/2, 1/3] [−140−1]
BBf(9) 6 [243/2, 1/3] [−150−1]
BBf(10) 7 [729/2, 1/3] [−160−1]
BBf(11) 10 [27/2, 25/3, 1/5] [−1300−1200−1]
BBf(12) 13 [81/2, 25/3, 1/5] [−1400−1200−1]
BBf(13) 17 [81/2, 125/3, 1/5] [−1400−1300−1]
BBf(14) 21 [243/2, 125/3, 1/5] [−1500−1300−1]
BBf(15) 28 [1/45, 4/5, 3/2, 25/3] [0−2−120−1−1100−12]
BBf(16) 53 [1/45, 4/5, 3/2, 125/3] [0−2−120−1−1100−13]
BBf(17) 107 [5/6, 49/2, 3/5, 40/7] [−1−110−100201−10301−1]
BBf(18) 211 [5/6, 49/2, 3/5, 80/7] [−1−110−100201−10401−1]
BBf(19) 370 [5/6, 49/2, 3/5, 160/7] [−1−110−100201−10501−1]
BBf(20) 746 [7/15, 22/3, 6/77, 5/2, 9/5] [−1−1+1+1−1+1+1+1−1−1−1+1+2−1]
BBf(21) ≥ 31,957,632 [7/15, 4/3, 27/14, 5/2, 9/5] [0−1−112−100−130−1−101002−10]
BBf(22) >1.146×1062 [1/12, 9/10, 14/3, 11/2, 5/7, 3/11] [−2−1000−12−1001−1010−10001001−100100−1]
BBf(23) >4.393×10124 [10/3, 9/14, 5/4, 121/2, 7/5, 3/11] [1−1100−120−10−20100−1000200−1100100−1]
BBf(24) >9.000×1014448[80] [14/15, 1/6, 11/3, 441/2, 5/7, 15/11] [1−1−110−1−10000−1001−12020001−100110−1]

Cyclic Tree Rewriting System (CTBB(n))

Runtime Champions
CTBB(2) 5[81]
CTBB(3) > 38[82]
CTBB(4) ≥ 672[83]
CTBB(5) ≥ 2^2^2^2^182[84]
CTBB(6) > 2↑↑↑131[85]
CTBB(7) > 4↑↑↑↑(4↑↑↑3)[86] [87]

Cyclic Tag (BBCT(n))

BBCT(n) Value Champion
BBCT(1) 1 empty
BBCT(2) 2 0
BBCT(3) 3 00
BBCT(4) 4 000
BBCT(5) 7 010_
BBCT(6) 8 010_0
BBCT(7) = 13 0110__
BBCT(8) ≥ 28 101_10_
BBCT(9) ≥ 717 1011_00_
BBCT(10) ≥ 1,626,862 1001_1_00
BBCT(11) ≥ 1,859,166 10_10010_0
BBCT(12) ≥ 6,328 0111__010_0
BBCT(13) ≥ 5,217,735 001110_1_0_0
BBCT(14) ≥ 154,171,565 01011__0_0100

Tiny Tag

n Runtime Champions
1 1 0
2 5 10
3 9 101
4 13 1001
5 15 10101
6 334 010111
7 404 1010111
8 670 11100101
9 12584 001101110
10 2180995 0100011110

Minsky Machines (MBB(n))

MBB(n)

Domain Halting Time Champion
MBB(1) 1 0+*
MBB(2) 3 0+B_0-B*
MBB(3) 5 0+B_0+C_0-C*
MBB(4) 10 0+B_1+C_0-BD_1-C*
MBB(5) 24 0-DB_0+C_1-ED_1+A_1-B*
MBB(6) 49 0+B_1-FC_1+D_0-CE_0+A_1-A*
MBB(7) 231 0+B_0+C_0+D_1-GE_1+F_0-EC_1-A*
MBB(8) ≥ 3,394 0+B_0+C_1-GD_1+E_0-DF_2-HG_2+A_2-D*
MBB(9) > 4.493 × 1074 0+B_0+C_1-HD_0-EG_0-FI_1+D_2+H_0+A_2-B*
MBB(10) > 10↑↑4.03 0+B_1-AC_2-ED_1+E_1+F_0-DG_2-JH_2+I_1-HE_2-A*
MBB(11) > 10↑↑17.74 0-KB_1-IC_1+D_1+E_2-CF_0-AG_0+H_1-GI_2+J_2+B_0-B*

Register Sigma function (MΣ(n,r))

Domain Sigma Champion
MΣ(0) 0
MΣ(1) 1 0+*
MΣ(2) 2 0+B_0+*
MΣ(3) 3 0+B_0+C_0+*
MΣ(4) 4 0+B_0+C_0+D_0+*
MΣ(5) 6 0+B_0+C_0+D_1-*E_1+A
MΣ(6) ≥ 9 1+B_1+C_0+D_0+E_0+F_1-C*
MΣ(7) ≥ 34 0+B_0+C_0+D_1-GE_1+F_0-EC_1-A*
MΣ(8) ≥ 520 0+B_1+C_2-AD_2+E_2+F_0-DG_1-H*_1-EB
MΣ(9) > 2.64 × 1073 0+B_0+C_1-HD_0-EG_0-FI_1+D_2+H_0+A_2-B*
MΣ(10) > 10↑↑4.03 0+B_1-AC_2-ED_1+E_1+F_0-DG_2-JH_2+I_1-HE_2-A*
MΣ(11) > 10↑↑17.74 0-KB_1-IC_1+D_1+E_2-CF_0-AG_0+H_1-GI_2+J_2+B_0-B*

Pebble Automaton (peBBle(n))

n peBBle(n) Champion
peBBle(1) 0 00
peBBle(2) 1 00_01
peBBle(3) 3 00_01_20
peBBle(4) 6 00_01_20_03
peBBle(5) 11[88] 00_11_03_21_04
peBBle(6) 17[89] 00_11_03_21_40_15
peBBle(7) 28[89] 00_11_03_21_10_33_61
peBBle(8) 63[90] 00_11_03_21_50_30_24_70
peBBle(9) 63577[91] 00_02_01_40_14_12_00_52_81
peBBle(10) 5778 00_02_01_40_14_12_00_17_63_18
peBBle(11) ≥ 810,626,821 00_00_30_40_12_51_07_20_41_12_19

PLUSMINUS

Initial string size "steps" Champion
1 1 +
2 3 -+
3 4 -++
4 7 -+++
5 15 ++++-
6 18 +++-++
7 20 ++++---
8 32 --++++++
9 44 ++++-+--+
10 196 +++++-+-+-
11 913 +++++-+--+-
12 5940 +++-++++++-+
13 728 +-++++++--++-
14 608 ++++-++++++---
15 2582 -+-++++++---+++
16 31441 +++++-++++-+-++-

Wang Tiles (BBWT(n))

n BBWT(n) Champion Image Reference
BBWT(1) 1 [1,0,0,0]
The definite champion for the largest valid square patch (1 by 1) made by a set of 1 Wang tile.
BBWT(2) 2 [1,0,2,0] [2,0,3,0]
The definite champion for the largest valid square patch (2 by 2) made by a set of 2 Wang tiles.
[92]
BBWT(3) 3 [1,0,2,0] [2,0,3,0] [3,0,4,0]
The definite champion for the largest valid square patch (3 by 3) made by a set of 3 Wang tiles.
[92]
BBWT(4) 4 [1,0,2,0] [2,0,3,0] [3,0,4,0] [4,0,5,0]
The definite champion for the largest valid square patch (4 by 4) made by a set of 4 Wang tiles.
[93]
BBWT(5) 6 [1,0,2,0] [2,0,3,0] [3,0,4,0] [4,6,1,5] [4,5,2,6]
The best known champion for the largest valid square patch (6 by 6) made by a set of 5 Wang tiles.
[94]
BBWT(6) 8 [1,0,2,0] [2,0,3,0] [3,0,4,0] [4,0,5,0] [5,7,1,6] [5,6,2,7]
The best known champion for the largest valid square patch (8 by 8) made by a set of 6 Wang tiles.
[94]
BBWT(7) 16 [4,0,3,0] [3,0,4,1] [3,1,3,2] [5,2,4,0] [4,1,4,2] [4,1,3,1] [3,2,5,0] [94][95]
BBWT(8) ≥ 17 [4,0,3,0] [3,0,4,1] [3,1,3,2] [5,2,4,0] [4,1,4,2] [4,1,3,1] [3,2,5,0] [0,0,3,1] [94][95]
BBWT(9) ≥ 17 [1,0,2,0] [2,0,3,0] [3,0,4,0] [4,0,5,0] [5,0,6,0] [6,0,7,0] [7,9,1,8] [7,8,2,9] [6,8,3,9]
The best known champion for the largest valid square patch (17 by 17) made by a set of 9 Wang tiles.
BBWT(10) ≥ 212 [96]

Branching Beaver (BrB(n))

Maximum Steps Function (BrB(n))

Domain Steps Champions
BrB(1) 3 1RA1RZ
BrB(2) 10 1RA0GB_1GA1RZ
BrB(3) ≥ 52 1RB0GB_0GC1RZ_1GC0RA
BrB(4) ≥ 4636 1RA0GB_1RC1RD_1GA0GC_1RZ0GA
BrB(2,3) ≥ 68 1RA2GA0BB_1BA2BA1RZ1RA2GA0BB_2BA1RZ1BA
BrB(2,4) ≥ 332,372 1RB2RB1GB1RZ_2GB3GA3RA1RA

Maximum Space Function (BrBspace(n))

Domain Max Space Champions
BrBspace(1) 2 1RA1RZ
BrBspace(2) 4 1RA0GB_1GA1RZ (and 10 others)
BrBspace(3) ≥ 22 1RB1RZ_0GC0BB_1GA0RA
BrBspace(4) ≥ 384 1RB0BB_0RC1RZ_0GA1GD_1RC0RA
BrBspace(2,3) ≥ 20 1RA2GA0BB_1BA2BA1RZ1RA2GA0BB_2BA1RZ1BA
BrBspace(2,4) ≥ 5996 1RB2GA3BA0RA_1GB2BB1RA1RZ

Turmites

Terminating Turmites (TT(n,k), 1D Turmites)

Where n is the amount of states and k is the amount of symbols.

Maximum steps for TT(n,k)

Domain Runtime Champions
TT(1) 3 1TA1PZ
TT(2) ≥ 13 1TB---_1PA0PB
TT(3) ≥ 82 1PB0PA_1TA0PC_1PA---
TT(4) ≥ 48,186 1TB1PA_1PC0PA_1TA0PD_---1TA
TT(1,3) ≥ 5 1TA2PA1PZ
TT(2,3) ≥ 223 1TB0PA2PA_2PA---1PA
TT(3,3) > 2.27×10248[97] 1PB0TC1PA_2PC1PZ2PA_2TC0PA2PC
TT(1,4) ≥ 9 1TA2PA3PA1PZ
TT(2,4) > 3.467*1015 1TA2PB3TB---_3TA1PB1TA1PA

Maximum score for TT(n,k)

Domain Score Champion
TT(3,3) ≥ 32,778[98] 1PB2PA0PC_2TB1PC2PB_2PB1PZ0PA

2D Turmites (turNing machines)

Domain Runtime Champion
TT2D(1) 5 1RA1PZ
TT2D(2) ≥ 121 1LA0LB_1PZ1RA
TT2D(3) ≥ 21,790 1RB1PA_1RB1RC_1PZ1PA
TT2D(4) ≥ 287,251 1PB0TD_0RA0PC_1PZ0TB_1PA0PA
TT2D(1,3) ≥ 9 1RA2RA1PZ
TT2D(2,3) ≥ 59,348,218 1RB2TB2PZ_1RA1PB1TB

Doodle Function (doodle(c,n))

doodle(1,n) = 1 and doodle(2,n) = n. Also note that doodle(c) = doodle(c,2).

2 Symbols: Runtime Champions
doodle(3,2) ≥ 487

Bug Function (Bug Game)

Bug(2,2) = 2

####
#S-#
#.F#
####

Bug(3,3) = 8

#####
#S..#
#.#.#
#.#F#
#####

Bug(4,4) = 20

######
#S...#
#..###
#....#
#..#F#
######

Bug(5,5) = 42

#######
#S...##
#.....#
#.....#
#.#.###
#.#..F#
#######

Bug(6,6) = 96

########
#S.....#
#.###.##
#.#...##
#.#....#
#..#.###
#..#..F#
########

Bug(7,7) = 218

#########
#S.###..#
#......##
#.#.##..#
#..#...##
#..#....#
#...#.###
#..#-..F#
#########

Bug(8,8) = 506

##########
#S.#.....#
#.#..##.##
#.#.##..##
#....##..#
#.#.#...##
#..##....#
#....#.###
#....#..F#
##########

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Determination of the fifth Busy Beaver value. The bbchallenge Collaboration et al. https://arxiv.org/abs/2509.12337
  2. ↑ 2.0 2.1 https://discord.com/channels/960643023006490684/1387426381041893417/1429556125539369040
  3. ↑ 3.0 3.1 Jeff Ketchersid, "BB(7): 1RB0RG_1RC1RB_0RD---_0LE0LD_0LF1LE_1RA1LF_0LD0RB (champ_231)". Github file, October 2026. Accessed 27 October 2026.
  4. ↑ 4.0 4.1 Jeff Ketchersid, "M8: an 8-state machine with f_ω(f_ω(f_ω(12))) < σ < f_ω(f_ω(f_ω(13)))". Github file, October 2026. Accessed 27 October 2026.
  5. ↑ Jeff Ketchersid, "h003: a 9-state machine above f_ω⁷(12), four levels above M8". Github file, October 2026. Accessed 27 October 2026.
  6. ↑ Jeff Ketchersid, "n1: a 10-state machine at level f_(ω+1)". Github file, October 2026. Accessed 27 October 2026.
  7. ↑ Jeff Ketchersid, "BB11/: 11 states, 2 symbols". Github file, October 2026. Accessed 27 October 2026.
  8. ↑ Jeff Ketchersid, "M12: a 12-state machine at level f_(ω+2)". Github file, October 2026. Accessed 27 October 2026.
  9. ↑ Jeff Ketchersid, "M13b: a 13-state machine at level f_(ω+2), six rounds deep". Github file, October 2026. Accessed 30 October 2026.
  10. ↑ Jeff Ketchersid, "M14d_18: a 14-state machine at level f_(ω+2), eighteen rounds deep". Github file, November 2026. Accessed 5 November 2026.
  11. ↑ Jeff Ketchersid, "M17_B: a 17-state machine at level f_(ω+3), three rounds". Github file, November 2026. Accessed 4 November 2026.
  12. ↑ Jeff Ketchersid, "M18_229round: an 18-state machine at level f_(ω+3), 229 rounds". Github file, November 2026. Accessed 5 November 2026.
  13. ↑ https://discord.com/channels/960643023006490684/1026577255754903572/1274471360206344213
  14. ↑ 14.0 14.1 Jeff Ketchersid, "BB29: a 29-state hydra machine at level f_{ω^ω}". Github file, October 2026. Accessed 30 October 2026.
  15. ↑ 15.0 15.1 Jeff Ketchersid, "BB31: a 31-state hydra machine above f_{ω^ω^ω^ω}(3)". Github file, October 2026. Accessed 30 October 2026.
  16. ↑ 16.0 16.1 Jeff Ketchersid, "BB33: a 33-state hydra machine above f_{ω^ω^ω^ω^ω^ω}(3)". Github file, October 2026. Accessed 30 October 2026.
  17. ↑ https://discord.com/channels/960643023006490684/1331570843829932063/1567585091172040726
  18. ↑ 18.0 18.1 https://discord.com/channels/960643023006490684/1026577255754903572/1328863966688182345
  19. ↑ 19.0 19.1 19.2 Jeff Ketchersid, "The BB(4,3) champion, machine-checked". Github file, October 2026. Accessed 2 November 2026.
  20. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1568460630002892892
  21. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1568651597318463620
  22. ↑ 22.0 22.1 S. Ligocki. "BB(3,4) > Ack(14)." https://www.sligocki.com/2024/05/22/bb-3-4-a14.html Blog post, 2024. Accessed 15 August 2025.
  23. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1564816765031288876
  24. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1567782759185784953
  25. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1564866772941672489
  26. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1566039528819400716
  27. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1566103427316977789
  28. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1566111131926274121
  29. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1566410612949385317
  30. ↑ 30.0 30.1 S. Ligocki, "BB(2,6) > 10↑↑10↑↑10↑↑3". Blog post, 2023. Accessed 15 August 2025.
  31. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1566700247881883699
  32. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1566703228169486477
  33. ↑ 33.0 33.1 https://discord.com/channels/960643023006490684/1084047886494470185/1567192072165924935
  34. ↑ 34.0 34.1 https://discord.com/channels/960643023006490684/1084047886494470185/1568599154039586929
  35. ↑ 35.0 35.1 https://discord.com/channels/960643023006490684/1084047886494470185/1568093269123145840
  36. ↑ https://discord.com/channels/960643023006490684/960643023530762341/1563057558011252761
  37. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1567559567519522909
  38. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1567910427856470071
  39. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1563070360956698804
  40. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1563070360956698804
  41. ↑ 41.0 41.1 Scott Aaronson. "The Busy Beaver Frontier". https://www.scottaaronson.com/papers/bb.pdf
  42. ↑ John Carrino, "Coq-BBB4"
  43. ↑ Nick Drozd. https://scottaaronson.blog/?p=8088#comment-1981333
  44. ↑ Nick Drozd. "BBB(3,3) > 10↑↑6". Accessed 15 August 2025.
  45. ↑ 45.0 45.1 Nick Drozd. "A Tetrational Self-Cleaning Turing Machine". Blog post. Accessed 17 October 2026.
  46. ↑ 46.0 46.1 Nick Drozd, "Blanking Beavers". Blog post, February 2021. Accessed 15 August 2025.
  47. ↑ racheline, September 2025. Discord message
  48. ↑ Charlie Reams. October 2026. Discord message
  49. ↑ 49.0 49.1 Charlie Reams, GitHub https://github.com/calr3/bbbb
  50. ↑ 50.0 50.1 J. Hertel, "Computing the Uncomputable Rado Sigma Function". The Mathematica Journal vol. 11 (2009).
  51. ↑ https://discord.com/channels/960643023006490684/1243312334907375676/1389807954013978756
  52. ↑ https://discord.com/channels/960643023006490684/1243312334907375676/138980795401397875
  53. ↑ 53.0 53.1 https://discord.com/channels/960643023006490684/1243312334907375676/1389809599955210362
  54. ↑ https://discord.com/channels/960643023006490684/1243312334907375676/1389807954013978756
  55. ↑ https://discord.com/channels/960643023006490684/1243312334907375676/1389817569342652578
  56. ↑ 56.0 56.1 https://discord.com/channels/960643023006490684/1243312334907375676/1389820614415618109
  57. ↑ 57.0 57.1 https://discord.com/channels/960643023006490684/1239205785913790465/1400255249847025776
  58. ↑ 58.0 58.1 58.2 Nick Drozd, "Latest Beeping Busy Beaver Results". Blog post, February 2022. Accessed 15 August 2025.
  59. ↑ Nick Drozd, "A New Record in Self-Cleaning Turing Machines". Blog post, July 2021. Accessed 3 November 2026.
  60. ↑ Nick Drozd, "Blanking Beavers: Results and Open Problems". Blog post, October 2026. Accessed 4 November 2026.
  61. ↑ https://discord.com/channels/960643023006490684/1369339127652159509/1374531970830307409
  62. ↑ 62.0 62.1 62.2 Nick Drozd, "Blanking Beavers". Blog post, February 2021. Accessed 3 November 2026.
  63. ↑ Shawn Ligocki, "Skelet #1 is infinite ... we think". Blog post, March 2023. Accessed 3 November 2026.
  64. ↑ https://discord.com/channels/960643023006490684/1239205785913790465/1567517097360363621
  65. ↑ 65.0 65.1 https://discord.com/channels/960643023006490684/960643023530762341/1393716114952818829
  66. ↑ 66.0 66.1 https://discord.com/channels/960643023006490684/960643023530762341/1393716181214564353
  67. ↑ 67.0 67.1 https://discord.com/channels/960643023006490684/960643023530762341/1393716260587700447
  68. ↑ 68.0 68.1 https://discord.com/channels/960643023006490684/960643023530762341/1393716514234040341
  69. ↑ 69.0 69.1 https://discord.com/channels/960643023006490684/960643023530762341/1393768821478785207
  70. ↑ 70.0 70.1 Shawn Ligocki, List of long-running BB(3,3) TMs
  71. ↑ Nick Drozd, "The Shape of a Turing Machine". Blog post, September 2025. Accessed 4 November 2026.
  72. ↑ 72.0 72.1 https://discord.com/channels/960643023006490684/1084047886494470185/1564808804024197152
  73. ↑ 73.0 73.1 https://discord.com/channels/960643023006490684/1084047886494470185/1564866772941672489
  74. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1566710164482957434
  75. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1566818235800625315
  76. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1567350954573963377
  77. ↑ https://discord.com/channels/960643023006490684/1026577255754903572/1274471360206344213
  78. ↑ https://discord.com/channels/960643023006490684/1331570843829932063/1567585091172040726
  79. ↑ https://discord.com/channels/960643023006490684/1084047886494470185/1398753236835635252
  80. ↑ https://discord.com/channels/960643023006490684/1438019511155691521/1547182811713380383
  81. ↑ https://discord.com/channels/960643023006490684/960643023530762341/1440163057463726233
  82. ↑ https://discord.com/channels/960643023006490684/1438694294042181742/1440193579006951517
  83. ↑ https://discord.com/channels/960643023006490684/1438694294042181742/1443246244142252043
  84. ↑ https://discord.com/channels/960643023006490684/1438694294042181742/1443298934217900063
  85. ↑ https://discord.com/channels/960643023006490684/1438694294042181742/1442847677883875479
  86. ↑ https://discord.com/channels/960643023006490684/1438694294042181742/1442950825545564281
  87. ↑ https://discord.com/channels/960643023006490684/1438694294042181742/1442819117735346217
  88. ↑ https://discord.com/channels/960643023006490684/1535695107448381591/1536023084975525999
  89. ↑ 89.0 89.1 https://discord.com/channels/960643023006490684/1535695107448381591/1536608195156381747
  90. ↑ https://discord.com/channels/960643023006490684/1535695107448381591/1537528571394793563
  91. ↑ https://discord.com/channels/960643023006490684/1535695107448381591/1539048792400203796
  92. ↑ 92.0 92.1 https://discord.com/channels/960643023006490684/1529586687926210691/1530032750579417198
  93. ↑ https://discord.com/channels/960643023006490684/1529586687926210691/1530697443820437645
  94. ↑ 94.0 94.1 94.2 94.3 Yeyito, "BB_WT in Rocq: BB_WT(5) = 6, BB_WT(6) = 8, BB_WT(7) = 16, BB_WT(8) ≥ 17". Github document, November 2026. Accessed 7 November 2026.
  95. ↑ 95.0 95.1 https://discord.com/channels/960643023006490684/1529586687926210691/1567754354671493152
  96. ↑ Emmanuel Jeandel, Michaël Rao, "An aperiodic set of 11 Wang tiles". January 2021. Accessed 7 November 2026.
  97. ↑ https://discord.com/channels/960643023006490684/1243312334907375676/1535305073259974728
  98. ↑ https://discord.com/channels/960643023006490684/1243312334907375676/1533503518906912778