A111322 Numbers k such that 8 divides prime(1) + ... + prime(k).

11, 15, 17, 19, 21, 27, 29, 31, 37, 49, 71, 79, 83, 85, 95, 99, 101, 103, 107, 109, 111, 115, 119, 121, 135, 155, 159, 161, 163, 169, 171, 177, 181, 183, 185, 201, 205, 209, 213, 235, 237, 239, 247, 255, 257, 259, 261, 263, 273, 275, 279, 283, 285, 287, 305, 309, 317, 319

Offset: 1

Author

N. J. A. Sloane, Nov 05 2005

Keywords

• nonn

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007504, A103208, A111318, A111319, A111320, A111321, A111323, A111324, A111325, A111326, A111327.

Programs

Mathematica

Position[Accumulate@ Prime@ Range@ 320, ?(Mod[#, 8] == 0 &)][[All, 1]] (* _Michael De Vlieger, Feb 05 2021 *)

PARI

isok(n) = !(vecsum(primes(n)) % 8); \\ Michel Marcus, Feb 05 2021

PARI

lista(pmax) = {my(s = 0, k = 0); forprime(p = 2, pmax, k++; s += p; if(!(s % 8), print1(k, ", ")));} \\ Amiram Eldar, May 14 2024