OFFSET
0,3
COMMENTS
Euler transform of A008480.
FORMULA
G.f.: Product_{k>=1} 1/(1 - x^k)^A008480(k).
MAPLE
g:= proc(n) option remember; (l-> add(i, i=l)!/
mul(i!, i=l))(map(i-> i[2], ifactors(n)[2]))
end:
a:= proc(n) option remember; `if`(n=0, 1, add(a(n-j)*
add(d*g(d), d=numtheory[divisors](j)), j=1..n)/n)
end:
seq(a(n), n=0..60); # Alois P. Heinz, May 17 2019
MATHEMATICA
terms = 47; A[_] = 1; Do[A[x_] = 1/(1 - x) Product[A[x^Prime[k]], {k, 1, terms}] + O[x]^(terms + 1) // Normal, terms + 1]; CoefficientList[A[x], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, May 17 2019
STATUS
approved