OFFSET
0,2
FORMULA
G.f.: Product_{k>=1} 1 / (1 - x^k)^prime(k+1).
MAPLE
a:= proc(n) option remember; `if`(n=0, 1, add(a(n-j)*add(
d*ithprime(d+1), d=numtheory[divisors](j)), j=1..n)/n)
end:
seq(a(n), n=0..30); # Alois P. Heinz, Apr 21 2022
MATHEMATICA
nmax = 30; CoefficientList[Series[Product[1/(1 - x^k)^Prime[k + 1], {k, 1, nmax}], {x, 0, nmax}], x]
a[0] = 1; a[n_] := a[n] = (1/n) Sum[Sum[d Prime[d + 1], {d, Divisors[k]}] a[n - k], {k, 1, n}]; Table[a[n], {n, 0, 30}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Apr 21 2022
STATUS
approved