A074942 a(n) = phi(n) mod 3.

1, 1, 2, 2, 1, 2, 0, 1, 0, 1, 1, 1, 0, 0, 2, 2, 1, 0, 0, 2, 0, 1, 1, 2, 2, 0, 0, 0, 1, 2, 0, 1, 2, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 2, 0, 1, 1, 1, 0, 2, 2, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 2, 0, 2, 0, 2, 2, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 2, 0, 1, 1, 0, 1, 0, 2, 1, 1, 0, 0, 2, 0, 1, 0, 2, 0, 0, 0, 1, 1, 2, 0, 0, 0

Offset: 1

Author

Benoit Cloitre, Oct 04 2002

Keywords

• easy
• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000010, A010872, A074943, A084300.

Programs

Magma

[EulerPhi(n) mod 3: n in [1..110]]; // Vincenzo Librandi, Sep 04 2015

Mathematica

Table[Mod[EulerPhi[n], 3], {n, 100}] (* Vincenzo Librandi, Sep 04 2015 *)

PARI

a(n)=eulerphi(n)%3

Formula

a(n) = A000010(n) mod 3.

a(n) = A010872(A000010(n)). - Michel Marcus, Sep 05 2015