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 A156629 #2 Mar 30 2012 18:37:16 %S A156629 1,5,28,181,1333,11029,101351,1024949,11320359,135679037,1754890039, %T A156629 24375607333,362034474975,5727314152237,96171016597079, %U A156629 1708678290956405,32029999992261615,631834430396575613,13084795597366612231 %N A156629 Column 4 of square array A156628. %K A156629 nonn %O A156629 0,2 %A A156629 _Paul D. Hanna_, Feb 17 2009 %E A156629 More terms from _Paul D. Hanna_, Feb 20 2009