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 A021000 #7 Jun 01 2010 03:00:00 %S A021000 2,7,24,82,280,956,3264,11144,38048,129904,443520,1514272,5170048 %N A021000 Duplicate of A020727. %K A021000 dead %O A021000 0,1