OFFSET
1,3
COMMENTS
a(23) > 150000. - Robert Price, Apr 05 2015
LINKS
Eric L. F. Roettger, A Cubic Extension of the Lucas Functions, Ph. D. Dissertation, Dept. Math. and Statistics, Univ. Calgary, 2009 (see page 196).
MATHEMATICA
Select[Range[0, 3000], PrimeQ[7 3^(2 #) + 5 3^# + 1] &]
PROG
(Magma) [n: n in [0..1000] | IsPrime(7*3^(2*n)+5*3^n+1)]; // Vincenzo Librandi, Apr 06 2015
(PARI) is(n)=ispseudoprime(7*3^(2*n)+5*3^n+1) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Vincenzo Librandi, Jul 14 2013
EXTENSIONS
a(19)-a(22) from Robert Price, Apr 05 2015
STATUS
approved