A039706 a(n) = n-th prime modulo 8.

2, 3, 5, 7, 3, 5, 1, 3, 7, 5, 7, 5, 1, 3, 7, 5, 3, 5, 3, 7, 1, 7, 3, 1, 1, 5, 7, 3, 5, 1, 7, 3, 1, 3, 5, 7, 5, 3, 7, 5, 3, 5, 7, 1, 5, 7, 3, 7, 3, 5, 1, 7, 1, 3, 1, 7, 5, 7, 5, 1, 3, 5, 3, 7, 1, 5, 3, 1, 3, 5, 1, 7, 7, 5, 3, 7, 5, 5, 1, 1, 3, 5, 7, 1, 7, 3, 1, 1, 5, 7, 3, 7, 7, 3, 3, 7, 5, 1, 3, 5, 3, 5, 3, 1, 3

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• easy

Links

• Nathaniel Johnston, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A039701-A039705, A038194, A007652, A039709-A039715.

Programs

Magma

[p mod(8): p in PrimesUpTo(500)]; // Vincenzo Librandi, May 06 2014

Maple

seq(ithprime(n) mod 8, n=1..105); # Nathaniel Johnston, Jun 29 2011

Mathematica

Table[Mod[Prime[n], 8], {n, 105}] (* Nathaniel Johnston, Jun 29 2011 *)
Mod[Prime[Range[100]], 8] (* Vincenzo Librandi, May 06 2014 *)

PARI

primes(100)%8 \\ Charles R Greathouse IV, May 06 2014

Formula

Sum_k={1..n} a(k) ~ 4*n. - Amiram Eldar, Dec 11 2024