BB(2,6)
The 2-state, 6-symbol Busy Beaver problem, BB(2,6), is unsolved. With cryptids like Hydra in the preceding domain BB(2,5), we know that we must solve a Collatz-like problem in order to solve BB(2,6).
The current BB(2,6) champion 1RB3RB5RA1LB5LA2LB_2LA2RA4RB1RZ3LB2LA (bbch) was discovered by Pavel Kropitz in May 2023, proving the lower bound:
Top Halters
The highest known scoring machines are:
| TM | Approximate sigma score | Discoverer |
|---|---|---|
1RB3RB5RA1LB5LA2LB_2LA2RA4RB1RZ3LB2LA (bbch)
|
10 ↑↑↑ 3 | Pavel Kropitz |
1RB3LA4LB0RB1RA3LA_2LA2RA4LA1RA5RB1RZ (bbch)
|
10 ↑↑ 91 | Pavel Kropitz |
1RB2LA1RA4LA5RA0LB_1LA3RA2RB1RZ3RB4LA (bbch)
|
10 ↑↑ 70 | Shawn Ligocki |
1RB2LB1RZ3LA2LA4RB_1LA3RB4RB1LB5LB0RA (bbch)
|
10 ↑↑ 69.68 | Andrew Ducharme |
1RB2LB0RA2RA5RA1LB_2LA4RB3LB2RB0RB1RZ (bbch)
|
10 ↑↑ 54.90 | Andrew Ducharme* |
1RB3RB1LB5LA2LB1RZ_2LA3RA4RB2LB0LA4RB (bbch)
|
10 ↑↑ 42.17 | Andrew Ducharme* |
1RB3LB0RB5RA1LB1RZ_2LB3LA4RA0RB0RA2LB (bbch)
|
10 ↑↑ 40.07 | Andrew Ducharme* |
1RB3LB3RB4LA2LA4LA_2LA2RB1LB0RA5RA1RZ (bbch)
|
10 ↑↑ 21.54 | Andrew Ducharme* |
1RB2LB3LA1RA0RA1RZ_1LA2RB1LB4RB5RA3LA (bbch)
|
10 ↑↑ 20.58 | Shawn Ligocki |
1RB0RA3RB0LB1RA2LA_2LA4LB1RA3LB5LB1RZ (bbch)
|
10 ↑↑ 17.53 | Andrew Ducharme* |
All decimal places are truncated. Discoverers are asterisked where it is unclear if the TM had been found but unreported by someone previously (namely Shawn Ligocki).
Filtering
Starting from Terry Ligocki's holdouts list of 22,302,296 TMs, additional filtering has been performed:
(done to reduce column size: = % Reduced, = Compute Time (core-hours), = Decided, = Processed)
| Done by | Holdout TMs | TMs/sec/core | Description | Data | ||||
|---|---|---|---|---|---|---|---|---|
| Input | Output | |||||||
| Terry Ligocki | 22,302,296 | 20,246,662 | 9.2% | 23.0 | 24.80 | 269.09 | MitM_CTL RWL_mod sim 1001 maxT 3000 H 6 mod 2 n 6 run | Google Drive |
| Terry Ligocki | 20,246,662 | 19,134,631 | 5.5% | 83.4 | 3.71 | 67.46 | MitM_CTL RWL_mod sim 1001 maxT 10000 H 6 mod 2 n 8 run | |
| Terry Ligocki | 19,134,631 | 5,443,318 | 71.6% | 46.6 | 81.69 | 114.17 | chr_LRUH 20 chr_H 12 MitM_CTL NG maxT 10000 NG_n 3 run | |
| Terry Ligocki | 5,443,318 | 3,400,118 | 37.5% | 16.3 | 34.87 | 92.90 | chr_LRUH 8 chr_H 4 MitM_CTL NG maxT 10000 NG_n 3 run | |
| Terry Ligocki | 3,400,118 | 3,303,416 | 2.8% | 14.1 | 1.90 | 66.82 | MitM_CTL RWL_mod sim 1001 maxT 10000 H 8 mod 3 n 6 run | |
| Terry Ligocki | 3,303,416 | 3,249,427 | 1.6% | 16.5 | 0.91 | 55.59 | chr_LRUH 0 chr_H 0 MitM_CTL NG maxT 30000 NG_n 7 run | |
| Terry Ligocki | 3,249,427 | 3,155,741 | 2.9% | 13.4 | 1.94 | 67.25 | MitM_CTL RWL_mod sim 1001 maxT 10000 H 6 mod 2 n 6 run | |
| Terry Ligocki | 3,155,741 | 2,246,891 | 28.8% | 14.1 | 17.93 | 62.24 | chr_LRUH 8 chr_H 8 MitM_CTL NG maxT 30000 NG_n 2 run | |
| Terry Ligocki | 2,246,891 | 2,143,803 | 4.6% | 7.5 | 3.82 | 83.19 | MitM_CTL RWL_mod sim 1001 maxT 10000 H 3 mod 3 n 1 run | |
| Terry Ligocki | 2,143,803 | 1,938,663 | 9.6% | 7.5 | 7.58 | 79.21 | MitM_CTL CPS_LRU sim 1001 maxT 10000 LRUH 8 H 1 tH 1 n 4 run | |
| Terry Ligocki | 1,938,663 | 1,885,153 | 2.8% | 7.5 | 1.98 | 71.72 | chr_LRUH 14 chr_H 12 MitM_CTL NG maxT 10000 NG_n 2 run | |
| Terry Ligocki | 1,885,153 | 1,848,887 | 1.9% | 10.5 | 0.96 | 49.68 | MitM_CTL RWL_mod sim 1001 maxT 10000 H 3 mod 1 n 12 run | |
| Terry Ligocki | 1,848,887 | 1,816,027 | 1.8% | 7.6 | 1.20 | 67.77 | chr_LRUH 18 chr_H 8 MitM_CTL NG maxT 10000 NG_n 5 run | |
| Terry Ligocki | 1,816,027 | 1,688,951 | 7.0% | 10.4 | 3.40 | 48.66 | MitM_CTL CPS_LRU sim 1001 maxT 30000 LRUH 4 H 2 tH 0 n 2 run | |