A267094 Primes p such that p*2^p + p + 2 is also prime.

3, 5, 11, 17, 31, 43, 139, 173, 3709, 161923

Offset: 1

Author

Emre APARI, Jan 11 2016

Keywords

• nonn
• hard
• more

Comments

Primes p such that A069229(n)+2 is prime. - Michel Marcus, Jan 12 2016

a(11) > 612649. - Robert Price, May 22 2016

Examples

			p=11: ((2^11)*11)+11+2 = 22541 (is prime).
		

Crossrefs

Cf. A069229.

Programs

Magma

[p: p in PrimesUpTo(200) | IsPrime(p*2^p+p+2)]; // Vincenzo Librandi, Jan 19 2016

Mathematica

Select[Prime[Range[4000]], PrimeQ[# 2^# + # + 2] &] (* Vincenzo Librandi, Jan 19 2016 *)

PARI

lista(nn) = forprime(p=2, nn, if(ispseudoprime(p*2^p + p + 2), print1(p, ", "))); \\ Altug Alkan, Jan 12 2016

Extensions

a(10) from Giovanni Resta, Apr 10 2016