A362339 a(n) = n! * Sum_{k=0..floor(n/4)} (-k)^k / (k! * (n-4*k)!).

1, 1, 1, 1, -23, -119, -359, -839, 78961, 722737, 3623761, 13297681, -2115602279, -27917827079, -195909017303, -980236890359, 219254440161121, 3780662914771681, 34105981790126881, 216149350680413857, -62275804867272039479, -1325952502191492278039

Offset: 0

Author

Seiichi Manyama, Apr 17 2023

Keywords

• sign

Links

• Eric Weisstein's World of Mathematics, Lambert W-Function.

Crossrefs

Cf. A069856, A362337, A362338.

Cf. A362349.

Programs

PARI

my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(x)/(1+lambertw(x^4))))

Formula

E.g.f.: exp(x) / (1 + LambertW(x^4)).