OFFSET
0,5
FORMULA
E.g.f.: Product_{k>=1} (1 + (-x)^k)^((-1)^k*mu(k)/k).
E.g.f.: exp(-x*(1 + x))*g(x)^2, where g(x) = e.g.f. of A005388.
MATHEMATICA
nmax = 23; CoefficientList[Series[Exp[x + 2 Sum[x^(2^k)/2^k, {k, 2, nmax}]], {x, 0, nmax}], x] Range[0, nmax]!
nmax = 23; CoefficientList[Series[Product[(1 + (-x)^k)^((-1)^k MoebiusMu[k]/k), {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, May 28 2019
STATUS
approved