A346941 E.g.f.: Product_{k>=1} 1 / (1 - x^k)^cos(x).

1, 1, 4, 15, 90, 555, 4815, 41034, 443268, 4977381, 64274655, 857332366, 13328296014, 207666642131, 3620701556017, 65845797790798, 1294049887432888, 26168756518235801, 576107273399556987, 12940593913711504118, 311924384689270232770, 7752903433736003497447, 203126367130952306670541

Offset

0,3

Links

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

Formula

E.g.f.: exp( cos(x) * Sum_{k>=1} sigma(k)*x^k/k ).

E.g.f.: exp( cos(x) * Sum_{k>=1} x^k/(k*(1 - x^k)) ).

Prog

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

Crossrefs

Cf. A000203, A346547, A346841, A347774.

Sequence in context: A306178 A304920 A076900 * A081011 A008829 A322920

Adjacent sequences: A346938 A346939 A346940 * A346942 A346943 A346944

Keyword

nonn

Author

Seiichi Manyama, Sep 18 2021

Status

approved