OFFSET
1,2
LINKS
N. J. A. Sloane, Transforms
EXAMPLE
The initial coefficients of successive iterations of g.f. A(x) = x/(1 - x - x^2) are as follows:
n = 1: 0, (1), 1, 2, 3, 5, ... g.f. A(x)
n = 2: 0, 1, (2), 6, 17, 50, ... g.f. A(A(x))
n = 3: 0, 1, 3, (12), 48, 197, ... g.f. A(A(A(x)))
n = 4: 0, 1, 4, 20, (102), 532, ... g.f. A(A(A(A(x))))
n = 5: 0, 1, 5, 30, 185, (1165), ... g.f. A(A(A(A(A(x)))))
MATHEMATICA
Table[SeriesCoefficient[Nest[Function[x, x/(1 - x - x^2)], x, n], {x, 0, n}], {n, 18}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Apr 06 2018
STATUS
approved