A284660 Terms of A161897 that are not in A005385.

3083, 4931, 6563, 9923, 166667, 865643, 1306667, 2266883, 3367367, 3906563, 4128959, 5493179, 5591039, 6040187, 9122963, 9402179, 9871403, 10174343, 13081379, 13756403, 14924003, 16550243, 24165287, 29492747, 32140859, 34633427, 38425643, 42249587, 42258779, 43014659, 45067523, 52678643

Offset

1,1

Comments

Primes p such that q = (p-1)/2 is composite, 3^q == 1 (mod p) and 3^(q-1) == 1 (mod p-1).

All terms == 5 (mod 6).

Links

Robert Israel, Table of n, a(n) for n = 1..212

Example

p = 3083 is in the sequence because it is prime, q = (3083-1)/2 = 23*67 is composite, 3^q == 1 (mod p) and 3^(q-1) == 1 mod (p-1).

Maple

filter:= p -> isprime(p) and not isprime((p-1)/2) and
   3&^((p-3)/2)  mod (p-1) = 1 and
   3 &^((p-1)/2) mod p = 1;
select(filter, [seq(p, p=5..10^7, 6)]); # Robert Israel, Mar 31 2017

Crossrefs

Cf. A005385, A161897.

Sequence in context: A045083 A186470 A322607 * A234781 A045079 A195811

Adjacent sequences: A284657 A284658 A284659 * A284661 A284662 A284663

Keyword

nonn

Author

Robert Israel, Mar 31 2017

Status

approved