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 A006510 M5135 #12 Jun 13 2012 12:35:24 %S A006510 2,3,5,7,23,67,89,4567,78901,678901,23456789,45678901,9012345678901 %N A006510 Duplicate of A006055. %D A006510 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %K A006510 dead %O A006510 1,1 %A A006510 _N. J. A. Sloane_, Jun 13 2012