A175171 Primes p such that 3*2^p-1 is also prime.

2, 3, 7, 11, 43, 103, 827, 7559, 26459, 164987

Offset

1,1

Comments

These are the primes in A002235. [R. J. Mathar, May 02 2010]

Links

Table of n, a(n) for n=1..10.

Example

For p=2, 3*2^2-1=11; p=3, 3*2^3-1=23; p=7, 3*2^7-1=383

Prog

(Magma) [p: p in PrimesUpTo(7000) | IsPrime(3*2^p-1) ];

Crossrefs

Cf. A002235.

Sequence in context: A072534 A056292 A106125 * A073609 A267091 A053781

Adjacent sequences: A175168 A175169 A175170 * A175172 A175173 A175174

Keyword

nonn,more

Author

Vincenzo Librandi, Mar 09 2010

Extensions

3 more terms from R. J. Mathar, May 02 2010

Status

approved