BB(2,7)
The 2-state, 7-symbol Busy Beaver problem, BB(2,7), 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(2,7).
The 2-state, 7-symbol Busy Beaver problem, BB(2,7), 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(2,7).