login
A060910
E.g.f.: exp(x*exp(x*exp(x)) + 1/2*x^2*exp(x*exp(x))^2 + 1/4*x^4*exp(x*exp(x))^4).
0
1, 1, 4, 25, 200, 1941, 22552, 304207, 4660224, 79627609, 1496962736, 30645682299, 677868344056, 16102526543533, 408764126148120, 11042583947604871, 316299747976627808, 9574687031473970673
OFFSET
0,3
REFERENCES
I. P. Goulden and D. M. Jackson, Combinatorial Enumeration, Wiley, N.Y., 1983.
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 = 4.
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Apr 07 2001
STATUS
approved