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 A299999 #19 Apr 23 2018 11:57:52 %S A299999 1,4,192,100352 %N A299999 Duplicate of A007341. %K A299999 dead %O A299999 0,2