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 A084987 #4 May 11 2007 03:00:00 %S A084987 11,101,181,191,919,10601,11411,16061,16661,18181,18481,19891,19991 %N A084987 Duplicate of A083185. %K A084987 dead %O A084987 1,1