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 A089121 #3 May 11 2007 03:00:00 %S A089121 2,5,5,17,13,37,5,13,41,101,61,29,17,197,113,257,29,13,181,401,17,97 %N A089121 Duplicate of A014442. %K A089121 dead %O A089121 1,1