OFFSET
1,2
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Andrew V. Lelechnko, Exponenital and infinitary divisors, arXiv:1405.7597 [math.NT], 2014, sequence f^E(n).
FORMULA
Multiplicative with a(p^e) = Sum_{d|e} A008683(e/d)*p^d.
Sum_{k=1..n} a(k) ~ c * n^2, where c = 0.43802998037163511363... = (1/2) * Product_{p prime} (1-1/p)*Sum_{k>=1} (Sum_{d|e} mu(k/d)*p^k/p^(2*k)). - Amiram Eldar, Oct 03 2023
MAPLE
MATHEMATICA
s[p_, e_] := DivisorSum[e, MoebiusMu[e/#]*p^#&];
a[n_] := a[n] = Times @@ s @@@ FactorInteger[n];
Array[a, 100] (* Jean-François Alcover, Dec 09 2017 *)
CROSSREFS
KEYWORD
nonn,easy,mult
AUTHOR
R. J. Mathar, Oct 05 2017
STATUS
approved