1,1

The total number of possible positions is a(1)+...+a(24) = 500995484682338672639.

However, not all of these positions are legal, i.e. reachable from the start position. - R. Stephan, Sep 18 2004

Jonathan Schaeffer, N. Burch, Yngvi Bjornsson, Akihiro Kishimoto, Martin Muller, Rob Lake, Paul Lu and Steve Sutphen. "Checkers Is Solved", Science, Vol. 317, September 14, 2007, pp. 1518-1522.

Jonathan Schaeffer, Yngvi Bjornsson, N. Burch, Akihiro Kishimoto, Martin Muller, Rob Lake, Paul Lu and Steve Sutphen. Solving Checkers, International Joint Conference on Artificial Intelligence (IJCAI), pp. 292-297, 2005. Distinguished Paper Prize.

J. Schaeffer, Table of n, a(n) for n = 1..24 [Taken fron link below]

J. Schaeffer, Chinook: Full sequence and more info

J. Schaeffer, Chinook: Publications

J. Schaeffer and R. Lake, Solving the game of checkers, in: R. Nowakowski (ed.), Games of No Chance (1996), p. 119-133.

Yngvi Bjornsson, N. Burch, Rob Lake, Joe Culberson, Paul Lu, Jonathan Schaeffer, Steve Sutphen, Chinook: Total Number of Positions

n=1: A red piece can go on any of 28 squares (it can't reside on the last row) and a red king can be on any of 32 squares. Double that to include black, total of 120.

A133803(n) = floor log a(n).

Sequence in context: A061541 A003438 A092710 this_sequence A035190 A035815 A001785

Adjacent sequences: A055210 A055211 A055212 this_sequence A055214 A055215 A055216

fini,nonn,full

Jud McCranie (j.mccranie(AT)comcast.net), Jun 23 2000