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 A119507 #7 Mar 30 2012 17:31:18
%S A119507 3,12,21,30,111,120,201,210,1020,1101,1110,2010,10020,10101,10110,
%T A119507 11010,20100,100020,100101,100110,101010,110100,200100,300000,1000101,
%U A119507 1000110,1001010,1010100,1100100,1200000,2000010,2100000,10000020,10000101
%N A119507 Members of A016052 whose digit sum is three.
%C A119507 A016052: a(n+1) = a(n) + sum of its digits, a(1) = 3.
%C A119507 Positions of these numbers in A016052: 1, 3, 5, 7, 15, 17, 25, 27, 85, 93, 95, 157, 589, 597, 599, 661, ...,.
%t A119507 lst = {}; a = 3; Do[ If[Plus @@ IntegerDigits@a == 3, AppendTo[lst, a]; Print[a]]; a = a + Plus @@ IntegerDigits@a, {n, 10^7}]; lst
%Y A119507 Cf. A016052.
%K A119507 nonn,base
%O A119507 1,1
%A A119507 _Zak Seidov_ and _Robert G. Wilson v_, May 27 2006
%E A119507 Edited by _Charles R Greathouse IV_, Aug 04 2010