A261872 a(n) = phi(n) mod 5, where phi is the Euler totient function.

1, 1, 2, 2, 4, 2, 1, 4, 1, 4, 0, 4, 2, 1, 3, 3, 1, 1, 3, 3, 2, 0, 2, 3, 0, 2, 3, 2, 3, 3, 0, 1, 0, 1, 4, 2, 1, 3, 4, 1, 0, 2, 2, 0, 4, 2, 1, 1, 2, 0, 2, 4, 2, 3, 0, 4, 1, 3, 3, 1, 0, 0, 1, 2, 3, 0, 1, 2, 4, 4, 0, 4, 2, 1, 0, 1, 0, 4, 3, 2, 4, 0, 2, 4, 4, 2, 1, 0, 3, 4, 2, 4, 0, 1, 2, 2, 1, 2, 0, 0, 0, 2, 2, 3, 3

Offset

1,3

Links

Antti Karttunen, Table of n, a(n) for n = 1..16384

Formula

a(n) = A000010(n) mod 5 = A010874(A000010(n)).

Mathematica

Table[Mod[EulerPhi[n], 5], {n, 110}]

Prog

(Magma) [EulerPhi(n) mod 5: n in [1..110]];
(PARI) a(n) = eulerphi(n) % 5; \\ Michel Marcus, Sep 05 2015

Crossrefs

Cf. A000010, A010874, A074942, A084300.

Sequence in context: A378751 A359382 A126768 * A021450 A239675 A289827

Adjacent sequences: A261869 A261870 A261871 * A261873 A261874 A261875

Keyword

nonn,easy

Author

Vincenzo Librandi, Sep 04 2015

Extensions

More terms from Antti Karttunen, Dec 04 2017

Status

approved