OFFSET
1,1
COMMENTS
a(12) > 65535. Presumably, a(12) = 149497 and a(13) = 388897.
EXAMPLE
4 is in this sequence because (3^4 - (-2)^4)/5 = 13 is prime.
MATHEMATICA
Select[Range[2000], PrimeQ[(3^# - (-2)^#)/5] &] (* Michael De Vlieger, Dec 09 2017 *)
PROG
(Magma) [n: n in [1..1000] | IsPrimePower((3^n-(-2)^n) div 5)];
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Juri-Stepan Gerasimov, Sep 04 2017
STATUS
approved