A004649 a(n) = prime(n) mod (n-1).

0, 1, 1, 3, 3, 5, 5, 7, 2, 1, 4, 5, 4, 5, 8, 11, 10, 13, 14, 13, 16, 17, 20, 1, 1, 25, 26, 25, 26, 7, 7, 9, 7, 13, 11, 13, 15, 15, 17, 19, 17, 23, 21, 21, 19, 27, 35, 35, 33, 33, 35, 33, 39, 41, 43, 45, 43, 45, 45, 43, 49, 59, 59, 57, 57, 1, 2, 7, 4, 3, 4, 7, 8

Offset: 2

Author

N. J. A. Sloane, Daniel Wild (wild(AT)edumath.u-strasbg.fr)

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 2..1000

Crossrefs

Cf. A004648, A004650.

Programs

Magma

[NthPrime(n) mod (n-1): n in [2..90]]; // Vincenzo Librandi, Sep 11 2014

Mathematica

Table[Mod[Prime[n], n - 1], {n, 2, 100}] (* Vincenzo Librandi, Sep 11 2014 *)

PARI

a(n) = prime(n) % (n-1) \\ Michel Marcus, Jun 12 2013