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 A100919 #3 Mar 30 2012 17:29:20 %S A100919 1,2,3,4,6,8,10,13,16,17,21,25,27,34,35,40,47,55,56,63,71,73,86,90, %T A100919 103,104,105,125,126,141,152,153,171,177,180,181,210,211,237,241,242, %U A100919 261,262,281,313,317,339,345,362,397,398,421,437,438,469,484,485,486,488 %N A100919 Index of the first occurrence of n in A100798. %Y A100919 Cf. A100798, A100920. %K A100919 easy,nonn %O A100919 1,2 %A A100919 _Ray Chandler_, Dec 08 2004