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 A031992 #11 Oct 18 2018 21:40:57 %S A031992 0,1,2,3,4,5,6,8,9,10,11,12,13,16,17,18,19,20,24,25,26,27,32,33,34,40, %T A031992 41,48,57,58,59,60,61,62,65,66,67,68,69,73,74,75,76,81,82,83,89,90,97, %U A031992 114,115,116,117,118,122,123,124,125,130,131,132 %N A031992 Duplicate of A023749. %K A031992 dead %O A031992 1,3