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 A169733 #2 Mar 30 2012 16:51:44 %S A169733 1,27,18,18,18,18,9,18,18,18,18,18,9,18,18,18,18,9,9,9,18,18,18,18,9, %T A169733 9,9,18,18,18,9,9,9,9,9,18,18,18,9,9,9,9,9,18,18,9,9,9,9,9,9,9,18,18, %U A169733 9,9,9,9,9,9,9,18,9,9,9,9,9,9,9,9,9,18,9,9,9,9,9,9,9,9,9,0,0,0,0,0,0,0,0,0 %N A169733 First differences of A169732, negated. %K A169733 nonn,base %O A169733 1,2 %A A169733 _N. J. A. Sloane_, May 01 2010