A327719 - OEIS

%I #10 Sep 23 2019 11:01:06

%S 1,1,1,1,2,3,3,3,4,6,7,9,10,12,14,16,21,24,27,32,37,45,52,59,69,76,89,

%T 103,118,137,148,173,197,225,256,280,324,362,409,462,508,579,644,720,

%U 811,892,1006,1114,1243,1389,1519,1701,1882,2090,2316,2538,2825,3110,3437,3795,4153

%N Expansion of Product_{k>=1} (1 + x^k/(1 + x^(2*k)/(1 + x^(3*k)/(1 + x^(4*k))))).

%H Seiichi Manyama, <a href="/A327719/b327719.txt">Table of n, a(n) for n = 0..1000</a>

%t nmax = 60; CoefficientList[Series[Product[(1 + x^k + x^(2*k) + x^(3*k) + 2*x^(4*k) + x^(5*k) + x^(6*k)) / (1 + x^(2*k) + x^(3*k) + x^(4*k) + x^(6*k)), {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Sep 23 2019 *)

%o (PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, 1+x^k/(1+x^(2*k)/(1+x^(3*k)/(1+x^(4*k))))))

%Y Cf. A327716, A327717, A327718, A327720.

%K nonn

%O 0,5

%A _Seiichi Manyama_, Sep 23 2019