A274683 White to move: King, Knight and Bishop vs. King: Number of positions with mate in n.

1840, 1200, 3216, 15960, 39752, 45192, 48396, 40408, 42720, 56240, 95208, 142084, 189592, 190296, 139684, 118004, 114200, 119780, 127480, 216552, 350136, 484868, 576832, 584456, 729040, 949808, 1278384, 1531500, 1434268, 859400, 261004, 33580, 1104

Offset: 1

Author

David A. Corneth, Jul 02 2016

Keywords

• nonn
• fini
• full

Comments

After n = 33, all terms are 0 so the sequence ends at n = 33.

GBR code is 0011. Longest checkmate under perfect play is in 33 (FEN 8/8/7N/8/8/8/8/K1k1B3 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

• Christian Posthoff, Günter Reinemann, Computerschach-Schachcomputer, Akademie-Verlag Berlin 1987, p. 52.

Links

• S. T. Dekker and H. J. van den Herik, GBR class 0011: a 33-move endgame, EG 78, 1984, p. 345-7.
• Steven J. Edwards, Endgame tablebase position count summaries, 1994.
• 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. A225556, A274684.

Extensions

Data and comments changed by Vaclav Kotesovec, Aug 01 2016