The Busy Beaver Problem
A NEW MILLENNIUM ATTACK
Busy Beaver r(4) Champion


r(4) Champion


r(4) Execution
    0     State 0
    1     State 1
    10    State 2
    10    State 3
   010    State 3
  0010    State 1
  0010    State 0
  0110    State 1
  0110    State 2
  0110    State 1
  01100   State 0
  01101   State 1
  011010  State 2
  011010  State 3
  011010  State 3
  011010  State 1
  011010  State 2
  011010  State 3
  011010  State 3
  011010  State 3
 0011010  State 1
 0011010  State 0
 0111010  State 1
 0111010  State 2
 0111010  State 1
 0111010  State 2
 0111010  State 3
 0111010  State 3
 0111010  State 3
 0111010  State 3
00111010  State 1
00111010  State 0
01111010  State 1
01111010  State 2
01111010  State 1
01111010  State 2
01111010  State 1
01111010  State 0
01111010  State 4
r(4) Information
Productivity : 5
Number of Steps to Halt : 38
Download : r(4) champion.tmo
Current Champions
n B(n) b(n) O(n) o(n)
1 1T 1T 1T 1T
2 2T 3T 2T 3T
3 3? 13R 3O 13R
4 5? 31R 8O 37R
5 11? 57R 15O 111O
6 25M 255M 239R 41606R
7 196M 13682M

8 672M 198339M


n P(n) p(n) R(n) r(n)
1 1T 2T 1T 2T
2 2T 4T 2T 4T
3 4R 14R 4R 14R
4 7R 32R 8R 38R
5 16R 112R 16R 112R
6 163R 27174R 240R 41607R

RSet by present RPI effort
MSet by Machado and Pereira
OSet by Oberschelp, et al.
TTrivial records
?Unknown origin

Also note: A solid yellow background indicates records have been explicitly confirmed by the present effort. A faded yellow indicates relative confidence but not yet an explicit proof.
Busy Beaver Research Team
Bram van Heuveln
Selmer Bringsjord
Boleslaw Szymanski
Carlos Varela
Kyle Ross
Owen Kellett
Shailesh Kelkar