A168367 Terms of A123239 which are 2 mod 3.

2, 11, 41, 59, 83, 107, 131, 179, 227, 251, 347, 419, 443, 467, 491, 563, 587, 659, 683, 761, 827, 947, 971, 1019, 1091, 1163, 1181, 1187, 1223, 1259, 1283, 1289, 1307, 1427, 1451, 1499, 1511, 1523, 1571, 1583, 1619, 1667, 1787, 1811, 1871, 1877

Offset

1,1

Comments

Terms of A123239 which are also primes in Z(w) where w = (-1+sqrt(-3))/2 is a cube root of unity.

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Mathematica

MangammalQ[p_] := Block[{k = 3}, While[k > 2, k = Mod[3 k, p]]; k != 2];
A168367 = Select[Prime[Range[290]], MangammalQ[#] && Mod[#, 3] == 2 &] (* Ray Chandler, Jul 21 2011 *)

Prog

(PARI) is(n)=if(n<9, return(n==2)); if(n%6!=5 || !isprime(n) || znorder(Mod(3, n)) == n-1, return(0)); my(m=Mod(3, n)); while(m!=1, m*=3; if(m==2, return(0))); 1 \\ Charles R Greathouse IV, May 21 2017

Crossrefs

Cf. A003627, A123239, A168325.

Sequence in context: A000822 A290175 A154813 * A247101 A080093 A175447

Adjacent sequences: A168364 A168365 A168366 * A168368 A168369 A168370

Keyword

nonn

Author

A.K. Devaraj, Nov 23 2009, Nov 25 2009

Extensions

Extended by Ray Chandler, Jul 21 2011

Definition simplified by Charles R Greathouse IV, May 21 2017

Status

approved