OFFSET
1
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..100000
FORMULA
a(n) = [A053669(n) == +1 (mod 6)], where [ ] is the Iverson bracket.
Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = Sum_{p prime, p == 1 (mod 6)} ((p-1)/(Product_{q prime, q <= p} q)) = 0.02897288485... . - Amiram Eldar, Apr 16 2024
MATHEMATICA
a[n_] := Module[{p = 2}, While[Divisible[n, p], p = NextPrime[p]]; Boole[Mod[p, 6] == 1]]; Array[a, 100] (* Amiram Eldar, Apr 16 2024 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 03 2022
STATUS
approved