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 A083543 #4 May 11 2007 03:00:00 %S A083543 3,12,28,42,2,6,120,195,234,6,21,2,84,1,744,558,78,780,210,336,72,6,10 %N A083543 Duplicate of A083538. %K A083543 dead %O A083543 1,1