A292750 Number of N(3)-good labeled Schroeder trees with 3n+1 leaves.

1, 1, 34, 5446, 2405116, 2261938588, 3887833883752, 11036586600027352, 48146117831841191344, 305819250310981380478960, 2712410196483210992702970400, 32485991726813047940443806486880, 511213599804308738544693971707418560, 10331797563908068914555424811425601583040

Offset

0,3

Links

Andrew Howroyd, Table of n, a(n) for n = 0..150

John Engbers, David Galvin, Clifford Smyth, Restricted Stirling and Lah numbers and their inverses, arXiv:1610.05803 [math.CO], 2016.

Prog

(PARI) seq(n) = {my(d=3, v=Vec(serlaplace(serreverse(sum(k=0, n, x^(1 + d*k)/(1 + d*k)!, O(x^(d*n+2))))))); vector(n+1, k, -(-1)^k*v[d*(k-1)+1])} \\ Andrew Howroyd, Dec 24 2025

Crossrefs

Sequence in context: A231084 A291976 A212035 * A199837 A267916 A005334

Adjacent sequences: A292747 A292748 A292749 * A292751 A292752 A292753

Keyword

nonn

Author

N. J. A. Sloane, Sep 22 2017

Extensions

a(7) onward from Andrew Howroyd, Dec 24 2025

Status

approved