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 A146497 #4 Dec 18 2015 18:17:14 %S A146497 0,20,17226,8194791,1995724092,51267367432 %N A146497 Number of n X n arrays of squares of integers with every (n-1)X(n-1) subblock summing to 13 and every element equal to at least one neighbor. %K A146497 nonn %O A146497 3,2 %A A146497 _R. H. Hardin_ Apr 14 2009