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 A037468 #10 Aug 03 2014 14:27:16
%S A037468 0,1,2,3,4,9,10,11,12,13,18,19,20,21,22,27,28,29,30,31,36,37,38,39,40,
%T A037468 81,82,83,84,85,90,91,92,93,94,99,100,101,102,103,108,109,110,111,112,
%U A037468 117,118,119,120,121,162,163,164,165,166,171,172,173,174,175
%N A037468 a(n)=Sum{d(i)*9^i: i=0,1,...,m}, where Sum{d(i)*5^i: i=0,1,...,m} is the base 5 representation of n.
%H A037468 Clark Kimberling, <a href="/A037468/b037468.txt">Table of n, a(n) for n = 0..1000</a>
%t A037468 Table[FromDigits[RealDigits[n, 5], 9], {n, 0, 100}]
%t A037468 (* _Clark Kimberling_, Aug 14 2012 *)
%Y A037468 Cf. A051382.
%K A037468 nonn,base
%O A037468 0,3
%A A037468 _Clark Kimberling_
%E A037468 Offset changed to 0 by _Clark Kimberling_, Aug 14 2012