A225555 Longest checkmate in king and princess versus king endgame on an n X n chessboard.

3, 8, 9, 11, 14, 17, 21, 24, 26, 30, 33, 37, 41, 44, 48, 51, 55, 59, 63, 67, 70, 75, 79, 83, 87, 91, 96, 101, 104, 109, 114, 118, 123, 127, 132, 136, 141, 145, 151, 154

Offset: 3

Author

Vaclav Kotesovec, May 10 2013

Keywords

• nonn

Comments

A princess moves like a bishop and a knight.

Examples

			Longest win on an 8x8 chessboard: Ka1 PRc1 - Kc2, 1.PRc1-f4 Kc2-b3 2.Ka1-b1 Kb3-c3! 3.Kb1-c1! Kc3-d4 4.Kc1-d2! Kd4-e4! 5.PRf4-e3! Ke4-e5! 6.Kd2-d3! Ke5-d6 7.Kd3-e4! Kd6-c7 8.Ke4-d5 Kc7-d7! 9.PRe3-f4 Kd7-e7! 10.PRf4-e5! Ke7-e8! 11.Kd5-d6 Ke8-d8 12.PRe5-f6 Kd8-c8! 13.Kd6-c6! Kc8-b8! 14.PRf6-d4! Kb8-a8 15.Kc6-b6! Ka8-b8! 16.PRd4-e6! Kb8-a8! 17.PRe6-c7#, therefore a(8) = 17.
		

Links

• V. Kotesovec, King and Two Generalised Knights against King, ICGA Journal, Vol. 24, No. 2, pp. 105-107 (2001)
• V. Kotesovec, Fairy chess endings on an n x n chessboard, Electronic edition of chess booklets by Vaclav Kotesovec, vol. 8, p.362 (2013), p. 542 (second edition, 2017).

Crossrefs

Cf. A225551, A225552, A225553, A225554, A225556, A225557, A227437.

Extensions

Terms a(41)-a(42) from Vaclav Kotesovec, Jul 19 2013