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 A024353 #6 May 11 2007 03:00:00 %S A024353 4,12,15,21,24,35,40,45,55,56,60,63,72,77,80,84,91,99,105,112,117 %N A024353 Duplicate of A020883. %K A024353 dead %O A024353 1,1