A294469 E.g.f.: 1/Product_{k>0} (1 - x^k/k)^k.

1, 1, 4, 18, 114, 810, 7140, 68880, 766920, 9304680, 125086080, 1814015280, 28588356720, 481128888240, 8678237087520, 166041500264640, 3371031116893440, 72153115744469760, 1627441316510929920, 38500269726897538560, 954533425718494702080

Offset

0,3

Links

Seiichi Manyama, Table of n, a(n) for n = 0..443

Formula

E.g.f.: exp(Sum_{k>=1} Sum_{j>=1} x^(j*k)/(k*j^(k-1))). - Ilya Gutkovskiy, Sep 12 2018

Mathematica

nmax = 20; CoefficientList[Series[Product[1/(1-x^k/k)^k, {k, 1, nmax}], {x, 0, nmax}], x] * Range[0, nmax]! (* Vaclav Kotesovec, Nov 01 2017 *)

Prog

(PARI) N=66; x='x+O('x^N); Vec(serlaplace(1/prod(k=1, N, (1-x^k/k)^k)))

Crossrefs

Cf. A007841, A181541, A294470, A294471.

Sequence in context: A062805 A326093 A222584 * A308462 A053483 A052617

Adjacent sequences: A294466 A294467 A294468 * A294470 A294471 A294472

Keyword

nonn

Author

Seiichi Manyama, Oct 31 2017

Status

approved