cp's OEIS Frontend

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.

A327044 Expansion of Product_{k>=1} 1/((1 - x^k) * (1 - x^(2*k)) * (1 - x^(3*k)) * (1 - x^(4*k)) * (1 - x^(5*k))).

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%I A327044 #10 Aug 17 2019 02:37:52
%S A327044 1,1,3,5,11,17,33,50,89,135,223,332,530,775,1190,1724,2576,3677,5380,
%T A327044 7586,10895,15203,21480,29666,41373,56593,77965,105755,144155,193947,
%U A327044 261894,349719,468193,620910,824743,1086661,1433205,1876865,2459100,3202155,4170043
%N A327044 Expansion of Product_{k>=1} 1/((1 - x^k) * (1 - x^(2*k)) * (1 - x^(3*k)) * (1 - x^(4*k)) * (1 - x^(5*k))).
%C A327044 Differs from A006170.
%C A327044 In general, for fixed m>=1, if g.f. = Product_{k>=1} (Product_{j=1..m} 1/(1 - x^(j*k))), then a(n,m) ~ sqrt(Gamma(m+1)) * HarmonicNumber(m)^((m+1)/4) * exp(Pi*sqrt(2*HarmonicNumber(m)*n/3)) / (2^((3*m+5)/4) * 3^((m+1)/4) * n^((m+3)/4)).
%H A327044 Vaclav Kotesovec, <a href="/A327044/b327044.txt">Table of n, a(n) for n = 0..10000</a>
%F A327044 a(n) ~ 137^(3/2) * exp(sqrt(137*n/10)*Pi/3) / (2880*sqrt(6)*n^2).
%t A327044 nmax = 50; CoefficientList[Series[Product[1/((1 - x^k) * (1 - x^(2*k)) * (1 - x^(3*k)) * (1 - x^(4*k)) * (1 - x^(5*k))), {k, 1, nmax}], {x, 0, nmax}], x]
%Y A327044 Cf. A000041, A002513, A327042, A327043.
%Y A327044 Cf. A006171.
%K A327044 nonn
%O A327044 0,3
%A A327044 _Vaclav Kotesovec_, Aug 16 2019