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 A090536 #4 Dec 05 2013 19:56:38 %S A090536 1,1,0,1,1,0,3,1,0,7,10,0,8,0,0,0,2,0,2,4,0,3,1,0,6,7,0,8,1,0,8,4,0,3, %T A090536 5,0,8,0,0,1,0,0,20,30,0,15,16,0,6,13,0,43,10,0,15,55,0,11,7,0,22,6,0, %U A090536 2,10,0,34,43,0,7,11,0,63,56,0,0,14,0,58,19,0,56,29,0,29,42,0,51,4,0,30 %N A090536 Location of 7 in A090535, or 0 if A090535 is 0. %C A090536 a(3n) = 0. %e A090536 a(10) = 7 as A090535(10) = 1117111111. %Y A090536 Cf. A090535, A090537, A090538. %K A090536 base,nonn %O A090536 1,7 %A A090536 _Amarnath Murthy_, Dec 08 2003 %E A090536 More terms from _David Wasserman_, Jan 03 2006