OFFSET
0,4
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..563
FORMULA
MATHEMATICA
nmax = 25; CoefficientList[Series[Exp[2 (Exp[x] - 1 - x - x^2/2)], {x, 0, nmax}], x] Range[0, nmax]!
a[0] = 1; a[n_] := a[n] = 2 Sum[Binomial[n - 1, k - 1] a[n - k], {k, 3, n}]; Table[a[n], {n, 0, 25}]
PROG
(PARI) my(x='x+O('x^30)); Vec(serlaplace(exp(2 * (exp(x) - 1 - x - x^2/2)))) \\ Michel Marcus, Nov 19 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Nov 19 2020
STATUS
approved