OFFSET
1
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..100000
FORMULA
Multiplicative with a(2^e) = A079978(e), a(3^e) = 0 for e >= 1, and a(p^e) = 1 for all primes p > 3, and e >= 1.
From Amiram Eldar, Jun 28 2024: (Start)
Dirichlet g.f.: zeta(s) * (1 - 1/3^s) / (1 + 1/2^s + 1/4^s).
Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = 8/21. (End)
MATHEMATICA
a[n_] := If[!Divisible[n, 3] && Divisible[IntegerExponent[n, 2], 3], 1, 0]; Array[a, 100] (* Amiram Eldar, Jun 28 2024 *)
PROG
(PARI) A374043(n) = (n%3 && !(valuation(n, 2)%3));
CROSSREFS
KEYWORD
nonn,mult,easy
AUTHOR
Antti Karttunen, Jun 27 2024
STATUS
approved