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 A084722 #3 Jan 09 2009 03:00:00 %S A084722 1,3,5,7,9,15,19,25,27,53,57,65,71,87,101,151,195,247,253,255,277,289, %T A084722 291 %N A084722 Duplicate of A083566. %K A084722 dead %O A084722 1,2