OFFSET
1,2
COMMENTS
119, 213, 1209 and 2469 proved prime by Primo v1.2.1. - Robert G. Wilson v Oct 17 2002
a(12) > 10^5. - Giovanni Resta, Mar 19 2014
MATHEMATICA
Do[ If[ PrimeQ[2 + 2^n + 3^n], Print[n]], {n, 1, 4000, 2}]
Select[Range[10000], PrimeQ[2 + 2^# + 3^#] &] (* _Vincenzo Librandi: Oct 05 2012 *)
PROG
(PARI) is(n)=ispseudoprime(2+2^n+3^n) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Zak Seidov, Oct 17 2002
EXTENSIONS
Edited and extended by Robert G. Wilson v, Oct 17 2002
a(10) from Vincenzo Librandi, Oct 05 2012
a(11) from Giovanni Resta, Feb 19 2013
STATUS
approved