OFFSET
1,2
COMMENTS
Numbers k such that k^(2^j) + 1 is a generalized Fermat prime for j=19.
1880370 is a member, but its position is not yet known. - Jeppe Stig Nielsen, Jan 24 2018
PrimeGrid has now tested and double checked the necessary candidates to prove that 1880370 is a(6). - Jeppe Stig Nielsen, Feb 20 2018
LINKS
H. Dubner and Y. Gallot, Distribution of generalized Fermat prime numbers, Math. Comp., 71 (2002), 825-832.
J. S. S. Nielsen, Generalized Fermat Primes sorted by base (See table at the bottom of the page.)
PrimeGrid, Announcement of k=75898
PrimeGrid, Announcement of k=341112
PrimeGrid, Announcement of k=356926
PrimeGrid, Announcement of k=475856
PrimeGrid, Announcement of k=1880370
PrimeGrid, Announcement of k=2061748
PrimeGrid, Announcement of k=2312092
PrimeGrid, GFN Prime Search Status and History
The Prime Pages, Database search results
PROG
(PARI) is(k)=isprime(k^524288+1) \\ Charles R Greathouse IV, Feb 20 2017
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
Felix Fröhlich, Jun 16 2014
EXTENSIONS
a(6) from Jeppe Stig Nielsen, Feb 20 2018
a(7) from Jeppe Stig Nielsen, Apr 27 2018
a(1) = 1 inserted and a(8) added by Jeppe Stig Nielsen, Sep 10 2018
a(9)-a(12) from Jeppe Stig Nielsen, Sep 21 2019
a(13) from Jeppe Stig Nielsen, Dec 27 2019
a(14) from Ray Chandler, Mar 28 2022
a(15)-a(17) communicated by Jeppe Stig Nielsen, Apr 01 2024
a(18)-a(21) from Jeppe Stig Nielsen, Jan 11 2025
a(22)-a(29) from Jeppe Stig Nielsen, Oct 27 2025
STATUS
approved