A379933 Expansion of e.g.f. 1/( exp(-x) - x )^2.

1, 4, 22, 158, 1408, 15002, 186100, 2634998, 41937136, 741170834, 14402727484, 305225470046, 7005711916840, 173134991854970, 4583675648417044, 129424786945875398, 3882446011526729440, 123304773913531035170, 4133369745467043807340, 145840627118145774415214

Offset: 0

Author

Seiichi Manyama, Jan 06 2025

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..410

Crossrefs

Cf. A072597, A379942, A379943.

Cf. A379934, A379936.

Cf. A358738, A377529.

Programs

PARI

my(N=20, x='x+O('x^N)); Vec(serlaplace(1/(exp(-x)-x)^2))

PARI

a(n) = n!*sum(k=0, n, (k+1)*(k+2)^(n-k)/(n-k)!);

Formula

E.g.f.: B(x)^2, where B(x) is the e.g.f. of A072597.

a(n) = n! * Sum_{k=0..n} (k+1) * (k+2)^(n-k)/(n-k)!.