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

1,2

Comments

a(18) > 10^5.

Links

Table of n, a(n) for n=1..17.

Example

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

Mathematica

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

Prog

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

Crossrefs

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

Sequence in context: A357110 A100195 A032396 * A305836 A233349 A233556

Adjacent sequences: A271881 A271882 A271883 * A271885 A271886 A271887

Keyword

nonn,more

Author

Robert Price, Apr 16 2016

Status

approved