Blanking Beaver
The Blanking Busy Beaver Function (BLB(n,m)) is a Busy Beaver Function which measures the largest amount of steps done by any Turing machine with n states and m symbols before blanking the tape. Blanking Busy Beaver machines are allowed to be halting or non-halting. As machines with just a single state cannot blank the tape, BLB(1,m) is nonexistent for any amount of symbols m. Similarly, BLB(n,1) is nonexistent for any amount of states n, as the tape of 1-symbol machines is always blank.
Champions
| 2 Symbols: | Steps | Champions |
|---|---|---|
| BLB(2) | 8[1] | 1RB0RA_1LB1LA (bbch)
|
| BLB(3) | 34[2] | 1RB1LB_1LA1LC_1RC0LC (bbch)
|
| BLB(4) | ≥ 32,779,477 | 1RB1LD_1RC1RB_1LC1LA_0RC0RD (bbch)
|
| BLB(5) | > 1014,006 | 1RB1LE_0LC0LB_0LD1LC_1RD1RA_0RC0LA (bbch)
|
| BLB(6) | > 10 ↑↑ 16 | 1RB0LD_1RC0RF_1LC1LA_0LE1RE_1LF0RB_0RC0RE (bbch)
|
| BLB(7) | > 10^183.76332[3] | 1RB0RF_1RC1RA_1LD0LA_0RG0RE_0RA1LF_0LE0LC_1RZ0RD (bbch)
|
| 3 Symbols: | Steps | Champions |
|---|---|---|
| BLB(2,3) | 77[2] | 1RB2LA0RB_1LA0LB1RA (bbch)
|
| BLB(3,3) | > 1042,745 | 1RB2RB1LA_2LC0LB2LB_2RC2RA0LC (bbch)
|
| 4 Symbols: | Steps | Champions |
|---|---|---|
| BLB(2,4) | ≥ 1,367,361,263,049[2] | 1RB2RA1RA2RB_2LB3LA0RB0RA (bbch)
|
| 5 Symbols: | Steps | Champions |
|---|---|---|
| BLB(2,5) | > 1032 | 1RB2RB4RA0RB2RA_2LB3LA0RB0RA1RB (bbch)
|
Instruction-limited Blanking Busy Beaver (BLBi(n))
BLBi(n) is the largest amount of steps taken by an n-instruction Turing machine when blanking the tape for the first time after having written a non-blank symbol on the tape.
Champions
Note that BLBi(1) and BLBi(2) are nonexistent as Turing machines with one or two instructions cannot blank the tape.
| Instructions | Steps | Champions |
|---|---|---|
| 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)
|
References
- ↑ Nick Drozd. "Blanking Beavers". Accessed 15 August 2025.
- ↑ 2.0 2.1 2.2 Nick Drozd. "Latest Beeping Busy Beaver Results". Accessed 15 August 2025.
- ↑ https://discord.com/channels/960643023006490684/1369339127652159509/1374531970830307409