A347893 - OEIS

A347893

E.g.f.: Product_{k>=1} (1 + x^k)^cos(x).

1, 1, 2, 9, 30, 195, 1545, 12474, 95564, 1199397, 14287845, 167518846, 2341450386, 34489552331, 540927170147, 10114629115798, 175935142966408, 3184271322683385, 68623817313870153, 1442553498798565142, 31856896467060026670, 787164874800260366287, 19097783293834170329239

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

Table of n, a(n) for n=0..22.

FORMULA

E.g.f.: exp( cos(x) * Sum_{k>=1} x^k / (k*(1 - x^(2*k))) ). - Ilya Gutkovskiy, Sep 18 2021

E.g.f.: exp( cos(x) * Sum_{k>=1} A000593(k)*x^k/k ). - Seiichi Manyama, Sep 18 2021

PROG

(PARI) N=40; x='x+O('x^N); Vec(serlaplace(prod(k=1, N, (1+x^k)^cos(x))))

(PARI) N=40; x='x+O('x^N); Vec(serlaplace(exp(cos(x)*sum(k=1, N, sigma(k>>valuation(k, 2))*x^k/k))))

CROSSREFS