A073464 a(n) = phi(n) mod PrimePi(n).

0, 0, 0, 1, 2, 2, 0, 2, 0, 0, 4, 0, 0, 2, 2, 2, 6, 2, 0, 4, 2, 4, 8, 2, 3, 0, 3, 8, 8, 8, 5, 9, 5, 2, 1, 0, 6, 0, 4, 1, 12, 0, 6, 10, 8, 1, 1, 12, 5, 2, 9, 4, 2, 8, 8, 4, 12, 7, 16, 6, 12, 0, 14, 12, 2, 9, 13, 6, 5, 10, 4, 9, 15, 19, 15, 18, 3, 12, 10, 10, 18, 13, 1, 18, 19, 10, 17, 16, 0, 0, 20, 12

Offset

2,5

Links

Vincenzo Librandi, Table of n, a(n) for n = 2..10000

Formula

a(n) = A000010(n) mod A000720(n).

Mathematica

a(n)=Table[Mod[EulerPhi[w], PrimePi[w]], {w, 2, 1000}]

Prog

(PARI) a(n) = eulerphi(n) % primepi(n); \\ Michel Marcus, Dec 11 2018
(Magma) [EulerPhi(n) mod #PrimesUpTo(n): n in [2..100]]; // Vincenzo Librandi, Dec 11 2018

Crossrefs

Cf. A000010, A000720.

Cf. A037228, A037171.

Cf. A073453, A073454, A073455, A073456, A073457, A072530, A072531, A073461, A073461.

Sequence in context: A103272 A065710 A089799 * A142242 A362634 A050314

Adjacent sequences: A073461 A073462 A073463 * A073465 A073466 A073467

Keyword

nonn

Author

Labos Elemer, Aug 02 2002

Status

approved