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 A278687 #6 Dec 05 2016 05:09:16 %S A278687 1,1,7,92,2102,66201,2651890,126928146,7060794663,447024321962 %N A278687 Number of non-equivalent ways to place n non-attacking ferses on an n X n board. %C A278687 A fers is a leaper [1, 1]. %C A278687 Rotations and reflections of placements are not counted. If they are to be counted, see A201861. %H A278687 Wikipedia, <a href="http://en.wikipedia.org/wiki/Fairy_chess_piece">Fairy chess piece</a> %Y A278687 Cf. A201861, A278688. %K A278687 nonn,more %O A278687 1,3 %A A278687 _Heinrich Ludwig_, Dec 02 2016