The Busy Beaver Game

The Busy Beaver Game

Presented at the book club at work. We read THE NEW TURING OMNIBUS, and you can find a description of The Busy Beaver Game there in chapter 39.

Busy Beavers describe a class of n-state, two-symbol Turing Machines whose aim is to write the greatest number of ones on an initial blank tape before halting. If we say that Σ(n) equals the greatest achievable number of ones for an n-state machine, then Σ can be shown to be non-computable. Moreover, it grows asymptotically faster than any other computable function.

Unfortunately, Speaker Deck doesn't seem to allow me to post the slide comments.

At the end of the deck I present plots on the number of ones and number of steps for 2 and 3-state Busy Beaver champions.

This time around I used Google Docs instead of Apple Keynote, and I think it's become a viable alternative. You can view the slides in your browser at


Christian Stigen Larsen

April 27, 2016