A081697 10-level labeled rooted trees with n leaves.

1, 1, 10, 145, 2755, 64660, 1804705, 58336855, 2141867440, 87998832685, 3998289746065, 198991311832840, 10762795518750121, 628439018694857887, 39390402253060922833, 2637469071097179922603, 187848412983167698626469, 14178423030415044515701642

Offset

0,3

References

J. Ginsburg, Iterated exponentials, Scripta Math., 11 (1945), 340-353.

T. Hogg and B. A. Huberman, Attractors on finite sets: the dissipative dynamics of computing structures, Phys. Review A 32 (1985), 2338-2346.

Links

Alois P. Heinz, Table of n, a(n) for n = 0..360

Formula

E.g.f. exp(exp(exp(exp(exp(exp(exp(exp(exp(exp(x)-1)-1)-1)-1)-1)-1)-1)-1)-1).

Prog

(PARI) a(n)=local(X); if(n<0, 0, X=x+x*O(x^n);  n!*
polcoeff(exp(exp(exp(exp(exp(exp(exp(exp(exp(exp(X)-1)-1)-1)-1)-1)-1)-1)-1)-1), n)).

Crossrefs

Cf. A000110, A000258, A000307, A000357, A001669.

Column k=9 of A144150.

Sequence in context: A113354 A027397 A305969 * A134526 A297714 A055761

Adjacent sequences: A081694 A081695 A081696 * A081698 A081699 A081700

Keyword

nonn

Author

Benoit Cloitre, Apr 23 2003

Status

approved