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A282669
Prime numbers p > 3 such that 2^p - 9 is prime.
0
5, 11, 17, 251, 563, 21011
OFFSET
1,1
COMMENTS
Let W = 2^p - 9 and s = (W+7)/(2*p), then 3^s == 4 (mod W) for terms 1..6.
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 *)
PROG
(PARI)
forprime(p=5, 10^5, W= 2^p-9; if(ispseudoprime(W), print1(p, ", ")))
CROSSREFS
Cf. A059610.
Sequence in context: A059960 A265850 A185365 * A271655 A294135 A265851
KEYWORD
nonn,more
AUTHOR
Dmitry Ezhov, Mar 07 2017
STATUS
approved