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 A121108 #6 Oct 04 2012 10:28:58 %S A121108 2677889,338688,27648,2688,768,336,54,20,0 %N A121108 Trajectory of 2677889 under "x -> product of digits of x" map. %C A121108 This is the smallest number of persistence 8 (cf. A003001). %H A121108 N. J. A. Sloane, <a href="http://neilsloane.com/doc/persistence.html">The persistence of a number</a>, J. Recreational Math., 6 (1973), 97-98. %Y A121108 Cf. A003001. %K A121108 nonn,fini,full,base %O A121108 1,1 %A A121108 _N. J. A. Sloane_, Aug 12 2006 %E A121108 Edited by _Charles R Greathouse IV_, Aug 06 2010