Busy Beaver ones function value $\Sigma(3)$
OrdinaryArtery, via Wikimedia Commons. CC BY-SA 4.0.
The maximal number of 1s that a $3$-state Turing machine can print on an initially blank tape before eventually halting.
Value: $6$
Updates
-
Lower bound: $6$
Reference unknown
[via Sequence A028444 in the OEIS] -
1965-04-01
Upper bound: $6$
Shen Lin and Tibor Rado. 1965. Computer Studies of Turing Machine Problems. J. ACM 12, 2 (April 1965), 196-212.
[via Sequence A028444 in the OEIS]