login
A074941
a(n) = sigma(n) mod 3.
16
1, 0, 1, 1, 0, 0, 2, 0, 1, 0, 0, 1, 2, 0, 0, 1, 0, 0, 2, 0, 2, 0, 0, 0, 1, 0, 1, 2, 0, 0, 2, 0, 0, 0, 0, 1, 2, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 2, 1, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 1, 2, 0, 0, 2, 0, 1, 0, 0, 2, 0, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 2, 0, 0, 1, 0, 0, 2, 0, 0
OFFSET
1,7
LINKS
FORMULA
a(n) = A010872(A000203(n)). - Antti Karttunen, Nov 05 2017
MAPLE
A074941:= n-> (numtheory[sigma](n) mod 3):
seq (A074941(n), n=1..105); # Jani Melik, Jan 26 2011
MATHEMATICA
a[n_] := Mod[DivisorSigma[1, n], 3]; Array[a, 100] (* Amiram Eldar, Jun 06 2022 *)
PROG
(PARI) a(n)=sigma(n)%3
CROSSREFS
Differs from A002324 for the first time at n=49, where a(49) = 0, while A002324(49) = 3.
Sequence in context: A357520 A145171 A117154 * A171774 A002324 A101671
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Oct 04 2002
STATUS
approved