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 A135279 #11 Jan 10 2019 23:04:11 %S A135279 1,2,2,3,5,6,8,9,11,14,15 %N A135279 Erroneous version of A005097. %K A135279 dead %O A135279 1,2