OFFSET
0,3
FORMULA
E.g.f.: exp(Sum_{k>=1} A001511(k)*x^k/k).
MATHEMATICA
nmax = 23; CoefficientList[Series[Product[1/(1 - x^2^k)^(1/2^k), {k, 0, Ceiling[Log[2, nmax]]}], {x, 0, nmax}], x] Range[0, nmax]!
nmax = 23; CoefficientList[Series[Exp[Sum[(IntegerExponent[k, 2] + 1) x^k/k, {k, 1, nmax}]], {x, 0, nmax}], x] Range[0, nmax]!
a[n_] := a[n] = (n - 1)! Sum[(IntegerExponent[k, 2] + 1) a[n - k]/(n - k)!, {k, 1, n}]; a[0] = 1; Table[a[n], {n, 0, 23}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Sep 10 2018
STATUS
approved