A033633 a(n) = n-th prime modulo 19.

2, 3, 5, 7, 11, 13, 17, 0, 4, 10, 12, 18, 3, 5, 9, 15, 2, 4, 10, 14, 16, 3, 7, 13, 2, 6, 8, 12, 14, 18, 13, 17, 4, 6, 16, 18, 5, 11, 15, 2, 8, 10, 1, 3, 7, 9, 2, 14, 18, 1, 5, 11, 13, 4, 10, 16, 3, 5, 11, 15, 17, 8, 3, 7, 9, 13, 8, 14, 5, 7, 11, 17, 6, 12, 18, 3, 9, 17, 2, 10

Offset: 1

Author

Armand Turpel (armand_t(AT)yahoo.com)

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. similar sequences listed in A242119.

Programs

Magma

[p mod(19): p in PrimesUpTo(500)]; // Vincenzo Librandi, May 07 2014

Mathematica

Mod[Prime[Range[100]], 19] (* Vincenzo Librandi, May 07 2014 *)

Formula

a(n) = A000040(n) mod 19.

Sum_k={1..n} a(k) ~ (19/2)*n. - Amiram Eldar, Dec 12 2024