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 A087399 #5 May 11 2007 03:00:00 %S A087399 25,121,5041 %N A087399 Duplicate of A085692. %K A087399 dead %O A087399 1,1