OFFSET
1,2
COMMENTS
Multiplicative because A341528 is.
LINKS
FORMULA
Multiplicative with a(p^e) = p^(e-1)*(q^e*(p*q-1)-p+1)/(q-1), where q = A151800(p). - Sebastian Karlsson, Sep 02 2021
Sum_{k=1..n} a(k) ~ c * n^3 / 3, where c = (1/zeta(3)) / Product_{p prime} (1 - (q(p)-p)/p^2 - q(p)/p^3) = 5.6488805... , and q(p) = A151800(p). - Amiram Eldar, Dec 24 2023
MATHEMATICA
f[p_, e_] := Module[{q = NextPrime[p]}, p^(e-1) * (q^e * (p*q-1) - p + 1)/(q-1)]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Dec 24 2023 *)
PROG
CROSSREFS
KEYWORD
nonn,mult
AUTHOR
Antti Karttunen, Aug 24 2021
STATUS
approved