OFFSET
1,2
COMMENTS
Möbius transform of A230593.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..20000
FORMULA
Sum_{k=1..n} a(k) ~ 3 * (1 + A085548) * n^2 / Pi^2. - Vaclav Kotesovec, Nov 20 2021
MATHEMATICA
a[n_] := DivisorSum[n, Boole[!CompositeQ[#]] * EulerPhi[n/#] &]; Array[a, 100] (* Amiram Eldar, Nov 17 2021 *)
PROG
(PARI) A349338(n) = sumdiv(n, d, eulerphi(n/d)*((1==d)||isprime(d)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 17 2021
STATUS
approved