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 A026199 #6 Jan 31 2020 08:53:21 %S A026199 1,2,5,3,4,11,13,6,17,7,8,23,9,10,29,31,12,35,37,14,41,15,16,47,49,18, %T A026199 53,19,20,59,21,22,65,67,24,71,25,26,77,27,28,83,85,30,89,91,32,95,33, %U A026199 34,101,103,36,107,109,38,113,39,40,119,121 %N A026199 Duplicate of A026183. %K A026199 dead %O A026199 1,2