A274693 Numbers n such that 4^n + 3^(n+1) is prime.

1, 2, 4, 5, 9, 10, 12, 17, 18, 29, 30, 40, 58, 82, 113, 129, 164, 192, 252, 524, 624, 766, 977, 1742, 2208, 2440, 3052, 4742, 5480, 16572, 17501

Offset: 1

Author

Robert Price, Jul 02 2016

Keywords

• nonn
• more

Comments

a(32) > 10^5.

Examples

			5 is a member since 4^5 + 3^6 = 1024 + 729 = 1753 which is a prime number.
		

Crossrefs

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

Programs

Magma

[n: n in [1..700] | IsPrime(4^n + 3^(n+1))]; // Vincenzo Librandi, Jul 03 2016

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, Jul 02 2016