A060909 E.g.f.: exp(x*exp(x*exp(x)) + 1/3*x^3*exp(x*exp(x))^3).

1, 1, 3, 18, 133, 1236, 13767, 176674, 2547561, 40614408, 708601771, 13433957934, 275200324797, 6061423076476, 142868492357151, 3587417860571346, 95560989416582353, 2690066742390963216, 79752454967110250835

Offset

0,3

References

I. P. Goulden and D. M. Jackson, Combinatorial Enumeration, Wiley, N.Y., 1983.

Links

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

Formula

E.g.f.: exp(Sum_{d|m} T_k^d/d), where T_k = x*exp(T_(k - 1)), k >= 1, T_0 = x; k = 2, m = 3.

Crossrefs

Cf. A000949 - A000951, A060905 - A060913.

Sequence in context: A322139 A236342 A369012 * A074545 A192462 A168072

Adjacent sequences: A060906 A060907 A060908 * A060910 A060911 A060912

Keyword

nonn

Author

Vladeta Jovovic, Apr 07 2001

Status

approved