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 A037948 #3 Sep 22 2004 03:00:00 %S A037948 2,3,5,7,2411 %N A037948 Duplicate of A007659. %K A037948 dead %O A037948 1,1