OFFSET
1,1
COMMENTS
The averages of this sequence are base values in generalized Fermat primes.
LINKS
Yves Gallot, Generalized Fermat Prime Search.
OEIS Wiki, Generalized Fermat numbers.
PrimeGrid, GFN Prime Search Status and History.
FORMULA
a(n) = (A014574(k))^(2^n)+1, for k = 1, 1, 1, 15, 5, 9, 82, 166, 117, 2055, 12, 1366, 6162, 14522, ...
EXAMPLE
198^(2^4)+1 = 5580113648647376991977566450378407937 is prime.
MATHEMATICA
t=Select[Table[Prime[n]+1, {n, 10^5}], PrimeQ[#1+1]&]; s:=t[[m]]; Table[m=1; While[!PrimeQ[s^(2^n)+1], m++]; s, {n, 1, 9}](* Last five terms obtained by intersection with Yves Gallot records.*)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Manuel Valdivia, Apr 09 2012
EXTENSIONS
a(15)-a(18) from Jeppe Stig Nielsen, Sep 14 2022
STATUS
approved