A175234 Primes p such that 2^p+15 is also prime.

2, 3, 5, 11, 23, 61

Offset

1,1

Comments

No additional terms through n=5000. - Harvey P. Dale, Apr 13 2014

a(7) > 5*10^5. - Robert Price, Sep 18 2015

Links

Table of n, a(n) for n=1..6.

Formula

A000040 INTERSECT A057197. [R. J. Mathar, May 02 2010]

Example

For p=2, 2^2+15=19; p=3, 2^3+15=23; p=5, 2^5+15=47.

Mathematica

Select[Prime[Range[1000]], PrimeQ[2^#+15]&] (* Harvey P. Dale, Apr 13 2014 *)

Prog

(Magma) [p: p in PrimesUpTo(6000) | IsPrime(2^p+15) ]

Crossrefs

Sequence in context: A338418 A261810 A176499 * A060696 A076051 A000628

Adjacent sequences: A175231 A175232 A175233 * A175235 A175236 A175237

Keyword

nonn

Author

Vincenzo Librandi, Mar 09 2010

Status

approved