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 A063931 #3 May 11 2007 03:00:00 %S A063931 6,12,15,20,24,28,30,35,40,45,42,48,54,60,66,56,63,70,77,84,91,72,80 %N A063931 Duplicate of A001283. %K A063931 dead %O A063931 2,1