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 A144260 #3 Mar 31 2012 12:35:07 %S A144260 1,1,1,4,2,1,1,1,16,1,8,1,1,4,1,16,2,1,256,1,1,1,128,4,1,1,1,1 %N A144260 Number of symmetric n X n binary matrices with each element equal to one minus the sum of its horizontal and vertical neighbors, modulo two. %C A144260 A075462 is a(n) without the symmetry restriction. %K A144260 nonn %O A144260 1,4 %A A144260 _R. H. Hardin_, Sep 16 2008