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 A072935 #3 May 11 2007 03:00:00 %S A072935 2,7,23,31,47,71,73,79,89,103,127,151,167,191,199,223,233,239,263,271 %N A072935 Duplicate of A072936. %K A072935 dead %O A072935 1,1