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 A144321 #8 Mar 30 2012 17:37:28
%S A144321 1,1,128,16384,2105280,269475840,34494988288,4415358500864,
%T A144321 565166154790272,72341267946323968,9259682331352899584,
%U A144321 1185239338413171146752,151710635321300728430592,19418961321126493239115776,2485627049104751885136429056
%N A144321 Shifts left when Dirichlet convolution (DC:(b,b)->a) applied 7 times.
%H A144321 Alois P. Heinz, <a href="/A144321/b144321.txt">Table of n, a(n) for n = 1..150</a>
%H A144321 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%p A144321 k:=7: with (numtheory): dc:= proc(b,c) proc(n) option remember; add (b(d) *c(n/d), d=`if`(n<0,{}, divisors(n))) end end: a:='a': b[1]:= dc(a,a): for t from 2 to k do b[t]:= dc(b[t-1], b[t-1]) od: a:= n-> `if`(n=1, 1, b[k](n-1)): seq (a(n), n=1..25);
%Y A144321 7th column of A144324.
%K A144321 eigen,nonn
%O A144321 1,3
%A A144321 _Alois P. Heinz_, Sep 17 2008