OFFSET
1,2
COMMENTS
The next terms are > 250000. - Robert Price, Oct 05 2015
Contains exactly the halved even terms of A057196.
EXAMPLE
For k = 15, 4^15 + 9 = 1073741833 is prime.
MATHEMATICA
Select[Range[0, 5000], PrimeQ[4^# + 9] &]
PROG
(Magma) [n: n in [0..700] | IsPrime(4^n+9)]; // Vincenzo Librandi, Oct 06 2015
(PARI) is(n)=ispseudoprime(4^n+9) \\ Charles R Greathouse IV, Jun 06 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Vincenzo Librandi, Oct 01 2012
EXTENSIONS
a(15)-a(16) derived from A057196 by Robert Price, Oct 05 2015
STATUS
approved