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 A024521 #4 Jun 29 2008 03:00:00 %S A024521 1,2,6,11,18,29,42,59,78,101,130,161,198,239,282,329,382,441,502,569 %N A024521 Erroneous version of A014284. %K A024521 dead %O A024521 1,2