OFFSET
1,1
LINKS
Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300
Wilfrid Keller, List of primes k.2^n - 1 for k < 300
Ray Ballinger, Proth Search Page
MATHEMATICA
Select[Range[1000], PrimeQ[227*2^# + 1] & ] (* Robert Price, Dec 19 2018 *)
PROG
(PARI) is(n)=ispseudoprime(227*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
EXTENSIONS
a(20)-a(25) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 19 2018
STATUS
approved