A271884 Numbers n such that 4^n-3^(n-1) is prime.

1, 2, 4, 6, 10, 12, 30, 42, 54, 166, 264, 886, 1476, 8412, 9576, 12426, 24076

Offset: 1

Author

Robert Price, Apr 16 2016

Keywords

• nonn
• more

Comments

a(18) > 10^5.

Examples

			4 is a member since 4^4 - 3^3 =  256 - 27 = 229 which is a prime number.
		

Crossrefs

Cf. A093713, A082103, A093717, A093793, A096185, A093794, A093795, A096186, A271883.

Programs

Mathematica

Select[Range[0, 100000], PrimeQ[4^# - 3^(# - 1)] &]

PARI

lista(nn) = for(n=1, nn, if(ispseudoprime(4^n-3^(n-1)), print1(n, ", "))); \\ Altug Alkan, Apr 16 2016