OFFSET
1,1
COMMENTS
a(22) > 150000. - Hans Havermann, Jul 18 2015
EXAMPLE
3 is in this sequence because 4^3 - 2^3 - 3 = 53.
MATHEMATICA
Select[Range[15000], PrimeQ[4^# - 2^# - 3] &]
PROG
(Magma) [n: n in [1..800] | IsPrime(4^n-2^n-3)];
(PARI) for(n=1, 500, if(ispseudoprime(4^n-2^n-3), print1(n, ", "))) \\ Derek Orr, Mar 03 2015
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Vincenzo Librandi, Mar 02 2015
EXTENSIONS
a(15)-a(21) from Hans Havermann, Jul 18 2015
STATUS
approved