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A057736
Primes p such that 2^p + 3 is prime.
4
OFFSET
1,1
COMMENTS
The next term p is greater than 100000, corresponding to a prime 2^p + 3 with more than 30000 digits. - Ryan Propper, Aug 24 2005
Next term > 2205444. - Joerg Arndt, Mar 07 2021
REFERENCES
J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 67, p. 24, Ellipses, Paris 2008.
MATHEMATICA
Select[Prime[Range[20]], PrimeQ[2^#+3]&] (* Harvey P. Dale, Jun 06 2022 *)
PROG
(Python)
from sympy import isprime, primerange
def afind(limit):
for p in primerange(2, limit+1):
if isprime(2**p + 3): print(p, end=", ")
afind(1000) # Michael S. Branicky, Mar 07 2021
CROSSREFS
Cf. A057737 (the corresponding primes).
Subsequence of A057732.
Sequence in context: A087358 A255357 A270002 * A181263 A130309 A090870
KEYWORD
more,nonn
AUTHOR
G. L. Honaker, Jr., Oct 29 2000
STATUS
approved