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 A143386 #7 Jul 31 2012 14:08:10 %S A143386 3,5,11,5,11,11,17,19,23,97,127,1009,167,269,963,479,3307,1453,37507, %T A143386 2357,599,17669,5527,3191,3251,70249,147773 %N A143386 Duplicate of A139430. %K A143386 dead %O A143386 1,1