A380879 - OEIS

A380879

Expansion of e.g.f. (1/x) * Series_Reversion( x * exp(-2*x*exp(x)) ).

1, 2, 16, 230, 4888, 138442, 4916140, 210270734, 10530743632, 604747157138, 39185881490644, 2828691317839510, 225137088955561144, 19588316964130880474, 1849745928662841982588, 188421660506420000503838, 20594905554562935801454240, 2404374864844251715105658146

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..17.

Index entries for reversions of series

FORMULA

E.g.f. A(x) satisfies A(x) = exp(2 * x * A(x) * exp(x * A(x))).

E.g.f.: B(x)^2, where B(x) is the e.g.f. of A360474.

a(n) = 2 * Sum_{k=0..n} k^(n-k) * (2*n+2)^(k-1) * binomial(n,k).

PROG

(PARI) a(n) = 2*sum(k=0, n, k^(n-k)*(2*n+2)^(k-1)*binomial(n, k));