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 A137619 #2 Mar 30 2012 19:00:33 %S A137619 1,4,5,12,15,28,33,40,55,44,71,72,105,96,117,152,147,188,225,224,245, %T A137619 276,299,306,353,356,405,416,451 %N A137619 a(n) is the maximal (nonredundant) number of switch flippings in a solution of the all-ones lights out problem on an n X n square. %D A137619 See A075462 for references. %Y A137619 Cf. A075464. %K A137619 hard,nonn %O A137619 1,2 %A A137619 _Jacob A. Siehler_, Apr 27 2008