A230809 Primes p of the form 60*n + 59 such that 2*p + 1 is also prime.

179, 239, 359, 419, 659, 719, 1019, 1439, 1499, 1559, 2039, 2339, 2399, 2459, 2699, 2819, 2939, 3299, 3359, 3539, 3779, 4019, 4919, 5039, 5279, 5399, 5639, 6899, 7079, 9059, 9419, 9479, 9539, 10799, 11519, 11579, 11699, 11939, 12119, 12899, 12959, 13619

Offset: 1

Author

Arkadiusz Wesolowski, Oct 30 2013

Keywords

• nonn

Comments

Primes p such that 2*p + 1 divides Lucas(p) and Mersenne(p).

Examples

			179 is in the sequence since it is prime and 359 is a factor of both Lucas(179) and Mersenne(179) = 2^179 - 1.
		

Links

• Eric Weisstein's World of Mathematics, Lucas Number
• Eric Weisstein's World of Mathematics, Mersenne Number

Crossrefs

Subsequence of A142799, of A215850, and of A239548. Cf. A000032, A001348, A002515.

Programs

Magma

[p : p in [59..13619 by 60] | IsPrime(p) and IsPrime(2*p+1)];

PARI

forstep(p=59, 13619, 60, if(isprime(p)&&isprime(2*p+1), print1(p, ", ")));

Formula

A005384 INTERSECT A142799.

A002515 INTERSECT A215850.