A347897 E.g.f.: Product_{k>=1} 1 / (1 - x^k)^(tan(x)/k).

1, 0, 2, 6, 36, 250, 1744, 18312, 158960, 2046672, 23152216, 332066240, 4628867680, 75851021376, 1225796994720, 22407297808560, 420285940934912, 8427749606274560, 177279678667864320, 3930905732908421376, 91016443490231306112, 2210008179756128156160, 55958663509700641300736

Offset

0,3

Links

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

Formula

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

Prog

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

Crossrefs

Cf. A000005 (d(n)), A346545, A347895, A347896.

Sequence in context: A058583 A345747 A075096 * A354413 A177373 A109284

Adjacent sequences: A347894 A347895 A347896 * A347898 A347899 A347900

Keyword

nonn

Author

Seiichi Manyama, Sep 18 2021

Status

approved