A282669 Prime numbers p > 3 such that 2^p - 9 is prime.

5, 11, 17, 251, 563, 21011

Offset: 1

Author

Dmitry Ezhov, Mar 07 2017

Keywords

• nonn
• more

Comments

Let W = 2^p - 9 and s = (W+7)/(2*p), then 3^s == 4 (mod W) for terms 1..6.

a(7) > 3480081 using A059610. - Michael S. Branicky, Jan 27 2025

Crossrefs

Prime terms of A059610.

Programs

Mathematica

Select[Prime[Range[3,565]],PrimeQ[2^#-9]&] (* The program generates the first five terms of the sequence. *) (* Harvey P. Dale, Aug 24 2024 *)

PARI

forprime(p=5, 10^5, W= 2^p-9; if(ispseudoprime(W), print1(p, ", ")))