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 A327726 #14 May 31 2024 14:35:20
%S A327726 1,1,1,3,3,4,7,8,10,17,20,24,36,42,52,72,85,103,139,164,197,256,301,
%T A327726 361,456,536,637,794,930,1098,1347,1571,1848,2235,2600,3042,3646,4228,
%U A327726 4922,5845,6754,7835,9229,10633,12284,14382,16519,19013,22127,25339,29073
%N A327726 Expansion of Product_{i>=1, j>=0} (1 + x^(i * 3^j)).
%C A327726 Weigh transform of A051064.
%F A327726 G.f.: Product_{k>=1} (1 + x^k)^A051064(k).
%F A327726 Let A(x) be the g.f. of this sequence, and B(x) be the g.f. of A000009, then B(x) = A(x)/A(x^3). - _Seiichi Manyama_, May 31 2024
%t A327726 nmax = 50; CoefficientList[Series[Product[(1 + x^k)^IntegerExponent[3 k, 3], {k, 1, nmax}], {x, 0, nmax}], x]
%t A327726 a[n_] := a[n] = If[n == 0, 1, Sum[Sum[(-1)^(k/d + 1) d IntegerExponent[3 d, 3], {d, Divisors[k]}] a[n - k], {k, 1, n}]/n]; Table[a[n], {n, 0, 50}]
%o A327726 (PARI) seq(n)={Vec(prod(k=1, n, (1 + x^k + O(x*x^n))^(1+valuation(k, 3))))} \\ _Andrew Howroyd_, Sep 23 2019
%Y A327726 Cf. A000041, A174065, A373219, A373220, A373221.
%Y A327726 Cf. A000009, A051064, A143374.
%K A327726 nonn
%O A327726 0,4
%A A327726 _Ilya Gutkovskiy_, Sep 23 2019