This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A225555 #12 Dec 01 2024 04:51:56 %S A225555 3,8,9,11,14,17,21,24,26,30,33,37,41,44,48,51,55,59,63,67,70,75,79,83, %T A225555 87,91,96,101,104,109,114,118,123,127,132,136,141,145,151,154 %N A225555 Longest checkmate in king and princess versus king endgame on an n X n chessboard. %C A225555 A princess moves like a bishop and a knight. %H A225555 V. Kotesovec, <a href="http://problem64.beda.cz/silo/kotesovec_icga_2001.pdf">King and Two Generalised Knights against King</a>, ICGA Journal, Vol. 24, No. 2, pp. 105-107 (2001) %H A225555 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Fairy chess endings on an n x n chessboard</a>, Electronic edition of chess booklets by Vaclav Kotesovec, vol. 8, p.362 (2013), p. 542 (second edition, 2017). %e A225555 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. %Y A225555 Cf. A225551, A225552, A225553, A225554, A225556, A225557, A227437. %K A225555 nonn %O A225555 3,1 %A A225555 _Vaclav Kotesovec_, May 10 2013 %E A225555 Terms a(41)-a(42) from _Vaclav Kotesovec_, Jul 19 2013