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 A152233 #9 Jan 09 2015 12:58:30 %S A152233 4,8,20,34,55,86,131,181,241,308,386,481,589,719,866,1033,1207,1391, %T A152233 1589,1810,2041,2279,2537,2812,3100,3392,3701,4021,4348,4694,5063, %U A152233 5446,5848,6275,6722,7186,7672,8180,8705,9250,9811,10391,10985,11602,12229 %N A152233 Similar to A072921 but starting with 4. %H A152233 Alois P. Heinz, <a href="/A152233/b152233.txt">Table of n, a(n) for n = 1..1000</a> %p A152233 b:= proc(n) option remember; local m; m:= a(n); `if`(n=1, 0, b(n-1)); while m>0 do %+ irem(m, 10, 'm') od; % end: a:= proc(n) option remember; `if`(n=1, 4, a(n-1) +b(n-1)) end: seq(a(n), n=1..50); # _Alois P. Heinz_, Oct 07 2009 %K A152233 nonn,base,easy %O A152233 1,1 %A A152233 _N. J. A. Sloane_, Oct 07 2009