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Expansion of Product_{m >= 1} (1-m*q^m)^13.
2

%I #11 Sep 08 2022 08:44:46

%S 1,-13,52,13,-546,676,1911,-962,-9282,-13624,53027,57408,-48334,

%T -222912,-558402,517803,1776723,2996227,-1100554,-14813461,-12542478,

%U -3043521,50552853,110798116,84474624,-114111322,-650898679,-771617782,-206121175,1974416808,4748905980,5776813289

%N Expansion of Product_{m >= 1} (1-m*q^m)^13.

%H G. C. Greubel, <a href="/A022673/b022673.txt">Table of n, a(n) for n = 0..1000</a>

%t With[{nmax = 50}, CoefficientList[Series[Product[(1 - k*q^k)^13, {k, 1, nmax}], {q, 0, nmax}], q]] (* _G. C. Greubel_, Feb 24 2018 *)

%o (PARI) m=50; q='q+O('q^m); Vec(prod(n=1,m,(1-n*q^n)^13)) \\ _G. C. Greubel_, Feb 24 2018

%o (Magma) Coefficients(&*[(1-m*x^m)^13:m in [1..40]])[1..40] where x is PolynomialRing(Integers()).1; // _G. C. Greubel_, Feb 24 2018

%K sign

%O 0,2

%A _N. J. A. Sloane_

%E Terms a(26) onward added by _G. C. Greubel_, Feb 24 2018