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 A189862 #6 Sep 12 2015 11:00:25 %S A189862 1,2,6,24,120,720,3720,22336,153796,1213344,10849504,108891704, %T A189862 1023690268,10593791168,119694887008,1472935989952 %N A189862 Number of ways to place n nonattacking composite pieces rook + rider[4,6] on an n X n chessboard. %C A189862 a(n) is also number of permutations p of 1,2,...,n satisfying |p(i+4k)-p(i)|<>6k AND |p(j+6k)-p(j)|<>4k for all i>=1, j>=1, k>=1, i+4k<=n, j+6k<=n %H A189862 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Number of ways of placing non-attacking queens, kings, bishops and knights</a> (in English and Czech) %H A189862 Wikipedia, <a href="http://en.wikipedia.org/wiki/Fairy_chess_piece">Fairy chess piece</a> %Y A189862 Cf. A000170, A189853, A189857, A189860 %K A189862 nonn,hard %O A189862 1,2 %A A189862 _Vaclav Kotesovec_, Apr 29 2011