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A153503
Primes p such that 2^(p-1)+3 is prime.
2
2, 3, 5, 7, 13, 17, 19, 29, 31, 229, 2371, 4003, 33029, 55457, 58313, 205963, 1875553
OFFSET
1,1
COMMENTS
A prime p is in the sequence if and only if p-1 is in A057732.
EXAMPLE
For p = 2, 2^(p-1)+3 = 5 is prime.
For p = 17, 2^(p-1)+3 = 65539 is prime.
For p = 31, 2^(p-1)+3 = 1073741827 is prime.
MATHEMATICA
Select[Prime[Range[3000]], PrimeQ[2^(# - 1) + 3] &] (* Vincenzo Librandi, Jun 09 2015 *)
PROG
(Magma) [p: p in PrimesUpTo(2000) | IsPrime(2^(p-1) + 3)]; // Vincenzo Librandi, Jun 09 2015
CROSSREFS
Cf. A057732 (numbers k such that 2^k + 3 is prime), A057736 (primes p such that 2^p + 3 is prime), A000043 (primes p such that 2^p - 1 is prime).
Sequence in context: A134207 A133244 A077040 * A049587 A293008 A038903
KEYWORD
nonn,more,hard
AUTHOR
Vincenzo Librandi, Dec 28 2008
EXTENSIONS
Edited and a(13)-a(15) (based on A057732) added by Klaus Brockhaus, Jan 06 2009
a(16) from Vincenzo Librandi, Jun 09 2015
a(17) from Amiram Eldar, Aug 01 2024
STATUS
approved