OFFSET
1,1
COMMENTS
Note that for the values 2 and 4 the primes are negative.
a(22) > 41358. - Jinyuan Wang, Jan 20 2020
All terms are even. - Elmo R. Oliveira, Nov 24 2023
LINKS
Henri Lifchitz and Renaud Lifchitz, Search for 2^n-23, PRP Top Records.
EXAMPLE
k = 6: 2^6 - 23 = 41 is prime.
k = 8: 2^8 - 23 = 233 is prime.
MATHEMATICA
Do[ If[ PrimeQ[ 2^n - 23 ], Print[ n ] ], { n, 1, 15000} ]
PROG
(PARI) is(n)=ispseudoprime(2^n-23) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Robert G. Wilson v, Sep 16 2000
EXTENSIONS
a(19)-a(21) from Jinyuan Wang, Jan 20 2020
a(22)-a(23) found by Henri Lifchitz, a(24)-a(27) found by Lelio R Paula, a(28)-a(29) found by Stefano Morozzi, added by Elmo R. Oliveira, Nov 24 2023
STATUS
approved