

A215962


Number of primes of the form 1 + b^16384 for 1 < b < 10^n.


0




OFFSET

1,6


COMMENTS

Primes 1 + b^16384 are a form of generalized Fermat primes.
It is conjectured that a(n) is asymptotic to 0.000488872*li(10^n)


LINKS



EXAMPLE

a(5) = 1 because the generalized Fermat numbers F_14(b) where b<10^5 are prime only for b = 67234.


PROG

(PARI) a(n) = sum(b=1, 10^n/21, isprime((2*b)^16384+1))


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



