OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..130
FORMULA
a(n) = [x^n] G_n, where G_n satisfies: (-1)^n*x = Sum_{i=0..n} (-1)^i*C(n,i)*(G_n*x)^(2^(n-i)).
a(n) ~ 2^(2*n) * n^(n - 3/2) / (sqrt(Pi) * exp(1/8)). - Vaclav Kotesovec, Jun 11 2018
MATHEMATICA
b[n_, k_, t_] := b[n, k, t] = If[t==0, 1, If[t==1, A[n-1, k], Sum[A[j, k]* b[n-j-1, k, t-1], {j, 0, n-2}]]];
a[n_] := If[n==0, 1, -Sum[Binomial[n, j]*(-1)^j*b[n+1, n, 2^j], {j, 1, n}]];
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Feb 02 2014
STATUS
approved