A368176 Expansion of e.g.f. -log(1 - x * exp(2*x)).

0, 1, 5, 26, 182, 1704, 19992, 281392, 4620464, 86707584, 1830550400, 42940149504, 1107995749632, 31188982438912, 951100528802816, 31234626965637120, 1099029746752575488, 41248797730190032896, 1644909773059509682176

Offset

0,3

Links

Table of n, a(n) for n=0..18.

Formula

a(n) = Sum_{k=1..n} (2*k)^(n-k) * (k-1)! * binomial(n,k).

a(n) ~ (n-1)! * 2^n / LambertW(2)^n. - Vaclav Kotesovec, Mar 11 2024

Prog

(PARI) a(n) = sum(k=1, n, (2*k)^(n-k)*(k-1)!*binomial(n, k));

Crossrefs

Cf. A009306, A009444, A368177.

Cf. A336950.

Sequence in context: A346545 A179513 A302896 * A175151 A121750 A143341

Adjacent sequences: A368173 A368174 A368175 * A368177 A368178 A368179

Keyword

nonn,easy

Author

Seiichi Manyama, Dec 14 2023

Status

approved