A155778 Primes p such that 2^p + p + 6 is also prime.

3, 5, 23, 83, 239, 66029

Offset

1,1

Comments

a(6), if it exists, is greater than 20000. - Dmitry Kamenetsky, Feb 06 2009

a(7), if it exists, is greater than 300000. - Michael S. Branicky, Sep 30 2024

Links

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

Mathematica

Select[Prime[Range[1000]], PrimeQ[(2^# + # + 6)]&] (* Vincenzo Librandi, Oct 30 2012 *)

Prog

(Magma) [p: p in PrimesUpTo(1000)| IsPrime(2^p + p +6)]; // Vincenzo Librandi, Oct 30 2012

Crossrefs

Sequence in context: A066411 A153410 A230080 * A209028 A178068 A018978

Adjacent sequences: A155775 A155776 A155777 * A155779 A155780 A155781

Keyword

nonn,more

Author

Vincenzo Librandi, Jan 27 2009

Extensions

a(5) from Dmitry Kamenetsky, Feb 06 2009

a(6) from Michael S. Branicky, Jan 30 2023

Status

approved