OFFSET
1,2
EXAMPLE
k = 5 gives 32 + 81 = 113, a prime.
MATHEMATICA
Do[p = 2^n + 3^(n-1); If[PrimeQ[p], Print[n]], {n, 1, 10^4}] (* Ryan Propper, Jul 23 2005 *)
PROG
(PARI) is(n)=ispseudoprime(2^n+3^(n-1)) \\ Charles R Greathouse IV, Jun 12 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Apr 14 2003
EXTENSIONS
a(37)-a(44) from Ryan Propper, Jul 23 2005
a(45)-a(54) from Michael S. Branicky, Jul 13 2023
STATUS
approved