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 A128023 #10 Jun 24 2019 22:15:35
%S A128023 1,1,1,2,3,5,9,16,28,51,92,169,312,580,1082,2029,3819,7214,13669,
%T A128023 25971,49468,94439,180666,346277,664852,1278561,2462414,4748941,
%U A128023 9170369,17729380,34314929,66485175,128940946,250297130,486291567,945566936
%N A128023 a(n) = A128022(n)/n.
%F A128023 a(1)=1, a(n) = ceiling(Sum_{k=1..n-1} A128022(k)/n).
%t A128023 f[l_List] := Block[{n = Length[l] + 1},Append[l, Ceiling[Sum[k*l[[k]], {k, n - 1}]/n]]];Nest[f, {1}, 36] (* _Ray Chandler_, Feb 12 2007 *)
%Y A128023 Cf. A128022.
%K A128023 easy,nonn
%O A128023 1,4
%A A128023 _Leroy Quet_, Feb 11 2007
%E A128023 Extended by _Ray Chandler_, Feb 12 2007