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 A064266 #6 Jul 14 2012 10:56:56 %S A064266 9,20,1,12,23,4,15,26,7,18,29,10,21,2,13,24,5,16,27 %N A064266 Lune of Jan 01 in Julian calendar for a year with Golden Number n. %D A064266 B. Blackburn and L. Hollford-Stevens, The Oxford Companion to the Year, Oxford, 1999; see p. 821. %H A064266 Eric Weisstein's World of Astronomy, <a href="http://scienceworld.wolfram.com/astronomy/GoldenNumber.html">Golden Number</a> %H A064266 <a href="/index/Ca#calendar">Index entries for sequences related to calendars</a> %K A064266 nonn,fini,full %O A064266 1,1 %A A064266 _N. J. A. Sloane_, Sep 24 2001