A174288 Primes p such that 8*2^(2p)-1 is also prime.

2, 5, 7, 29, 43, 1607, 4969, 9967, 22247, 699133, 1510687, 21321899

Offset: 1

Author

Vincenzo Librandi, Mar 15 2010

Keywords

• nonn
• more

Comments

These are the primes in A139481. - R. J. Mathar, Mar 17 2010

Examples

			For p = 2, 8*2^4-1 = 127; p = 5, 8*2^10-1 = 8191; p = 7, 8*2^14-1 = 131071.
		

Crossrefs

Cf. A139481.

Programs

Magma

[p: p in PrimesUpTo(4500)| IsPrime(8*2^(2*p)-1)];

Mathematica

Select[(MersennePrimeExponent[Range[48]] - 3) / 2, PrimeQ] (* Amiram Eldar, Jul 14 2025 *)

Extensions

a(7)-a(10) from Vincenzo Librandi, Jul 13 2025

a(11)-a(12) from Amiram Eldar, Jul 14 2025