OFFSET
0,3
FORMULA
a(0) = 1; a(n) = Sum_{k=1..n} binomial(n-1,k-1)*A007837(k)*a(n-k).
MATHEMATICA
nmax = 22; CoefficientList[Series[Exp[Product[(1 + x^k/k!), {k, 1, nmax}] - 1], {x, 0, nmax}], x] Range[0, nmax]!
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, May 20 2019
STATUS
approved