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 A146521 #4 Dec 18 2015 18:17:15 %S A146521 0,36,25148,18912868,9700090280,6565665508942 %N A146521 Number of n X n arrays of squares of integers summing to 27 with every element equal to at least one neighbor. %K A146521 nonn %O A146521 2,2 %A A146521 _R. H. Hardin_ Apr 14 2009