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 A143882 #5 Oct 20 2014 18:33:44 %S A143882 1,2,3,29,48,1401,1825,183270,194391,76221979,59133738,86201358557, %T A143882 54181631319,318503225414986,146475713866791 %N A143882 Number of ways of placing kings with no more than 3 mutual attacks on an n X n chessboard symmetric under horizontal reflection. %K A143882 nonn,more,hard %O A143882 0,2 %A A143882 _R. H. Hardin_, Sep 04 2008