%I #9 Aug 28 2018 13:06:25
%S 1,1,0,0,4,4,0,0,4,13,9,0,0,36,36,0,16,52,63,27,64,64,108,108,64,233,
%T 277,135,27,676,676,108,204,772,1333,765,528,420,2628,2628,528,1792,
%U 3892,3735,1251,5524,5380,4428,4684,6657,12843,10870,6703,3767,28232
%N Expansion of Product_{k>=1} (1 + k*x^(k^2))^k.
%H Vaclav Kotesovec, <a href="/A285242/b285242.txt">Table of n, a(n) for n = 0..10000</a>
%t nmax = 100; CoefficientList[Series[Product[(1 + k*x^(k^2))^k, {k,1,nmax}], {x,0,nmax}], x]
%t nmax = 100; s = 1 + x; Do[s *= Sum[Binomial[k, j]*k^j*x^(j*k^2), {j, 0, Floor[nmax/k^2] + 1}]; s = Select[Expand[s], Exponent[#, x] <= nmax &];, {k, 2, nmax}]; CoefficientList[s, x]
%Y Cf. A022629, A266891, A281790, A285240, A285243, A285244.
%K nonn
%O 0,5
%A _Vaclav Kotesovec_, Apr 15 2017