OFFSET
1,2
LINKS
Ray Ballinger, Proth Search Page
Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300
MATHEMATICA
Select[Range[4000], PrimeQ[23 2^# + 1] &] (* Vincenzo Librandi, Sep 26 2012 *)
PROG
(PARI) is(n)=ispseudoprime(23*2^n+1) \\ Charles R Greathouse IV, Jun 06 2017
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
EXTENSIONS
Added more terms (from http://www.prothsearch.com/riesel1.html), Joerg Arndt, Apr 07 2013
a(19) from Jeppe Stig Nielsen, Oct 11 2019
STATUS
approved