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 A193174 #20 Oct 22 2017 13:11:55 %S A193174 0,2,1,4,3,8,5,20,7,16,13,18,55,30,53,26,47,20,41 %N A193174 Duplicate of A126084. %K A193174 dead %O A193174 0,2