A007545 Number of chess games with n plies (another version). (Formerly M5100)

1, 20, 400, 8902, 197742, 4897256, 120921506, 3284294545, 88867026005

Offset

0,2

Comments

Up to a(6) this is the number of chess games with all legality constraints removed, even allowing the king to be captured. (This differs from the number of positions in suicide chess, as suicide chess contains compulsory captures.) - Richard Bean, Jun 18 2003

References

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=0..8.

Eric Weisstein's World of Mathematics, Chess

Index entries for sequences related to number of chess games

Crossrefs

Cf. A006494, A048987.

Sequence in context: A007577 A048987 A006494 * A055476 A223180 A041181

Adjacent sequences: A007542 A007543 A007544 * A007546 A007547 A007548

Keyword

fini,nonn,hard

Author

Ken Thompson (ken(AT)google.com)

Extensions

I am not sure of the precise rules that were used to compute these numbers. A006494 and A048987 are the preferred versions of this sequence. - N. J. A. Sloane.

Status

approved