A271884 - OEIS

%I #6 Apr 16 2016 11:43:05

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

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

%C a(18) > 10^5.

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

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

%o (PARI) lista(nn) = for(n=1, nn, if(ispseudoprime(4^n-3^(n-1)), print1(n, ", "))); \\ _Altug Alkan_, Apr 16 2016

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

%K nonn,more

%O 1,2

%A _Robert Price_, Apr 16 2016