A377690 E.g.f. satisfies A(x) = 1 + x * (exp(x*A(x)^3) - 1).

1, 0, 2, 3, 76, 545, 11166, 175777, 4012856, 96530625, 2685888730, 83721921041, 2843440273092, 107065956887617, 4332658616388662, 190612061432096865, 8961290146870598896, 451334805268791262337, 24156272027391899229234, 1371678815491898403876913

Offset

0,3

Links

Table of n, a(n) for n=0..19.

Formula

a(n) = n! * Sum_{k=0..floor(n/2)} (3*n-3*k)! * Stirling2(n-k,k)/( (n-k)! * (3*n-4*k+1)! ).

Prog

(PARI) a(n) = n!*sum(k=0, n\2, (3*n-3*k)!*stirling(n-k, k, 2)/((n-k)!*(3*n-4*k+1)!));

Crossrefs

Cf. A371262, A377687.

Sequence in context: A371143 A370988 A371269 * A306195 A091825 A166091

Adjacent sequences: A377687 A377688 A377689 * A377691 A377692 A377693

Keyword

nonn

Author

Seiichi Manyama, Nov 04 2024

Status

approved