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 A120180 #4 Jul 15 2012 14:47:00
%S A120180 3,3,4,5,5,6,7,8,10,11,13,15,18,21,24,28,33,39,45,53,61,72,84,98,114,
%T A120180 133,155,181,211,246,287,335,391,456,532,621,724,845,986,1150,1342,
%U A120180 1565,1826,2131,2486,2900,3383,3947,4605,5373,6268,7313,8532,9954,11613
%N A120180 a(1)=3; a(n)=floor((20+sum(a(1) to a(n-1)))/6).
%t A120180 Module[{lst={3}},Do[AppendTo[lst,Floor[(20+Total[lst])/6]],{100}];lst] (* _Harvey P. Dale_, Jul 15 2012 *)
%Y A120180 Cf. A073941, A112088, A072493.
%K A120180 nonn
%O A120180 1,1
%A A120180 _Graeme McRae_, Jun 10 2006
%E A120180 More terms from _Harvey P. Dale_, Jul 15 2012