A277507 E.g.f.: -1/((1-LambertW(-x))*(1-x)).

-1, 0, 0, 3, 28, 305, 3846, 57337, 998600, 20036529, 456403690, 11647754921, 329290975212, 10214585950153, 344897398385918, 12590837785019145, 494101941398352016, 20740772742716097377, 927276395603713539282, 43987299891665164562377, 2206610456287703987567540

Offset: 0

Author

Vaclav Kotesovec, Oct 18 2016

Keywords

• sign

Links

• G. C. Greubel, Table of n, a(n) for n = 0..385

Crossrefs

Cf. A277506, A277508.

Programs

Mathematica

CoefficientList[Series[-1/(1-LambertW[-x])/(1-x), {x, 0, 20}], x] * Range[0, 20]!

PARI

x='x+O('x^50); Vec(serlaplace(-1/((1 - lambertw(-x))*(1-x)))) \\ G. C. Greubel, Nov 08 2017

Formula

a(n) ~ n^(n-1) / (4*(1-exp(-1))).