OFFSET
1,4
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
FORMULA
a(n) = n - A173557(n).
Sum_{k=1..n} a(k) ~ c * n^2 / 2, where c = 1 - A307868 = 0.528319... . - Amiram Eldar, Dec 16 2023
MATHEMATICA
a[n_] := n - Times @@ (FactorInteger[n][[;; , 1]] - 1); a[1] = 0; Array[a, 100] (* Amiram Eldar, Dec 16 2023 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Antti Karttunen, Sep 16 2018
STATUS
approved