OFFSET
1,1
COMMENTS
Primes that are the sum of consecutive integers (k=0) and consecutive squares (k=1) are excluded. Values of k <= 16 were tested. The sequence A078902 lists some of the generalized Fermat primes. Bjorn and Riesel examined generalized Fermat numbers for n <= 11 and k <= 999.
LINKS
Anders Björn and Hans Riesel, Factors of Generalized Fermat Numbers, Mathematics of Computation, Vol. 67, No. 221, Jan., 1998, pp. 441-446.
Eric Weisstein's World of Mathematics, Generalized Fermat Number
EXAMPLE
a(1) = 3 because there are three Fermat primes (with k>1): 17, 257, 65537.
MATHEMATICA
lst={}; Do[prms=0; Do[If[PrimeQ[(n+1)^2^k+n^2^k], prms++ ], {k, 2, 16}]; AppendTo[lst, prms], {n, 16}]; lst
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
T. D. Noe, Jan 30 2003
STATUS
approved