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 A144819 #11 Dec 18 2020 18:45:45
%S A144819 1,1,6,36,231,1386,8496,50976,306956,1842276,11060586,66363516,
%T A144819 398229516,2389377096,14336517456,86019146316,516116428791,
%U A144819 3096698572746,18580200896796,111481205380776,668887287816276
%N A144819 Shifts left when Dirichlet convolution with a (DC:(b,a)->c) applied 5 times.
%H A144819 Alois P. Heinz, <a href="/A144819/b144819.txt">Table of n, a(n) for n = 1..1000</a>
%H A144819 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%p A144819 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:= proc(n, k) local a, b, t; b[1]:= dc(a,a); for t from 2 to k do b[t]:= dc(b[t-1],a) od: a:= n-> `if`(n=1, 1, b[k](n-1)); a(n) end: a:= n-> A(n,5): seq (a(n), n=1..30);
%t A144819 dc[b_, c_] := Module[{f}, f[n_] := f[n] = Sum[b[d] c[n/d], {d, If[n<0, {}, Divisors[n]]}]; f];
%t A144819 A[n_, k_] := Module[{a, b, t}, b[1] = dc[a, a]; For[t = 2, t <= k, t++, b[t] = dc[b[t-1], a]]; a = Function[m, If[m==1, 1, b[k][m-1]]]; a[n]];
%t A144819 a[n_] := A[n, 5];
%t A144819 Array[a, 30] (* _Jean-François Alcover_, Dec 18 2020, after Maple *)
%Y A144819 5th column of A144823.
%K A144819 eigen,nonn
%O A144819 1,3
%A A144819 _Alois P. Heinz_, Sep 21 2008