A274684 White to move: King and Queen vs. King: Number of positions with mate in n.

2448, 5012, 9064, 19964, 26164, 32064, 32104, 15000, 2680, 8

Offset

1,1

Comments

After n = 10, all terms are 0 so the sequence ends at n = 10.

GBR code is 1000. Longest checkmate under perfect play is in 10 (FEN 8/8/8/5k2/8/8/1Q6/K7 w - - 0 1). For path of moves, see k4it-link. Data is found using Kryukov link, "Endgame Tablebases online". FEN is found in Kryukov link, "Longest checkmates in chess".

The listed examples, or more generally up to 6 man positions can be examined using the k4it link.

References

Hans Zellner, International Computer Chess Association Journal, 1987, Vol. 10, No. 2, p. 95.

Links

Table of n, a(n) for n=1..10.

Steven J. Edwards, Endgame tablebase position count summaries, 1994.

EG 121, GBR class 1000.00, 1996, p. 873.

k4it, All 6-men tables online (except 5 vs. 1).

K. Kryukov, Endgame Tablebases Online

K. Kryukov, Longest checkmates in chess

Wikipedia, GBR code

Crossrefs

Cf. A225551, A274458, A274683.

Sequence in context: A256898 A255077 A183629 * A232141 A251338 A035772

Adjacent sequences: A274681 A274682 A274683 * A274685 A274686 A274687

Keyword

nonn,fini,full

Author

David A. Corneth, Jul 02 2016

Extensions

Data and comments changed by Vaclav Kotesovec, Aug 01 2016

Status

approved