1,2

John Tromp wrote a small C program to compute the number for boards up to size 4 X 5, given in above rec.games.go posting. Gunnar Farnebaeck (gunnar(AT)lysator.liu.se) wrote a pike script to compute the number by dynamic programming, which handles sizes up to 12 X 12 (available upon request).

British Go Association, Go

Sandy Harris, Number of Possible Outcomes of a Game.

John Tromp, Number of legal Go positions

John Tromp, Complexity of Chess and Go

3^(n*n) is a trivial upper bound.

The illegal 2 X 2 positions are the 2^4 with no empty points and the 4 X 2 having a stone adjacent to 2 opponent stones that share a liberty. That leaves 3^4-16-8 = 57 legal positions.

Sequence in context: A132783 A127455 A091749 this_sequence A093257 A069255 A065869

Adjacent sequences: A094774 A094775 A094776 this_sequence A094778 A094779 A094780

nonn

Jan Kristian Haugland (jankrihau(AT)hotmail.com), Jun 09 2004

More terms from John Tromp (tromp(AT)cwi.nl), Jan 27 2005

a(10) - a(13) from John Tromp (tromp(AT)cwi.nl), Jun 23 2005

a(14), a(15) from John Tromp (tromp(AT)cwi.nl), Sep 01 2005.

a(16) = 4813066963822755416429056022484299646486874100967249263944719599975607459850502222039591149331431805524655467453067042377. - John Tromp (tromp(AT)cwi.nl), Oct 06 2005

Michal Koucky should be credited for carrying most of the computational load for computing the n=14, 15 and 16 results with his file-based implementation.