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 A161419 #2 Mar 30 2012 17:34:00 %S A161419 0,0,0,6,0,6,0,12,6 %N A161419 First differences of A161418. %Y A161419 Cf. A160120, A161418, A161829, A161837. %K A161419 more,nonn %O A161419 1,4 %A A161419 _Omar E. Pol_, Jun 21 2009