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 A186517 #9 Jun 08 2014 04:05:09 %S A186517 0,1,1,3,8,34,201,2000,53397,10435175,49476809194 %N A186517 Duplicate of A094448. %K A186517 dead %O A186517 0,4