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%I #14 Mar 20 2022 04:26:26
%S 4,8,24,36,48,246,608,734,774,824,948,1244,3230,4656,5448,6360,7598,
%T 15390,48158,86754
%N Numbers k such that 4^k-3^(k+1) is prime.
%C a(21) > 10^5.
%e 8 is a member since 4^8 - 3^9 = 65536-19683 = 45853 which is a prime number.
%t Select[Range[4, 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 24 2016
%Y Cf. A093713, A082103, A093717, A093793, A096185, A093794, A093795, A096186, A271883.
%K nonn,more
%O 1,1
%A _Robert Price_, Apr 24 2016
%E Typo in a(11) corrected by _Georg Fischer_, Mar 19 2022