A130133 Terms in A015922 not divisible by 3.

1, 2, 4, 8, 248, 731, 1333, 3503, 17608, 35003, 50963, 62611, 82603, 90148, 94643, 106978, 201295, 231311, 253828, 335723, 364808, 374573, 425323, 490915, 592595, 628015, 725203, 984343, 1031803, 1112023, 1136195, 1376903, 1411343, 1430003, 1642798, 1926088

Offset: 1

Author

Zak Seidov, May 12 2007

Keywords

• nonn

Comments

Intersection of A015922 and A001651. - Michel Marcus, Oct 13 2013

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A001651, A015922, A130134.

Intersection with A033553 gives A277344.

Programs

Maple

a:= proc(n) option remember; local k;
      for k from 1+`if`(n=1, 0, a(n-1)) while
      irem(k, 3)=0 or 2&^k mod k <> 8 mod k do od; k
    end:
seq(a(n), n=1..30);  # Alois P. Heinz, Jun 04 2014

Mathematica

{1, 2, 4, 8} ~Join~ Select[Range[2 10^6], PowerMod[2, #, #] == 8 && !Divisible[#, 3]&] (* Jean-François Alcover, Nov 02 2020 *)

PARI

isok(n) = (n % 3) && (Mod(2^n, n) == Mod(8, n)); \\ Michel Marcus, Oct 13 2013

Extensions

a(17)-a(28) from Michel Marcus, Oct 13 2013

a(29)-a(36) from Alois P. Heinz, Jun 04 2014