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 A055371 #3 Mar 30 2012 17:37:11 %S A055371 1,-1,1,-1,0,5,-18,27,67,-496,496,6963,-24246,-148002,1138045,3360042, %T A055371 -58828040,-33243252,3312139446,-5235582541,-204462055464, %U A055371 726496668085,14922365946662,-84161948692035,-1310383972147810 %N A055371 Column 1 of triangle A055370. %K A055371 sign %O A055371 1,6 %A A055371 _Christian G. Bower_, May 16 2000