%I #16 Nov 28 2023 18:33:00
%S 1,3,6,7,10,15,30,34,54,58,103,105,205,223,279,741,2098,3523,9210,
%T 37674,89895,101509,217123
%N Numbers k such that 4^k + 33 is prime.
%C Contains exactly the halved even terms of A247953.
%C The next terms are > 2*10^5.
%e For k = 30, 4^30 + 33 = 1152921504606847009 is prime.
%t Select[Range[0, 250000], PrimeQ[4^# + 33] &]
%o (Magma) [n: n in [0..700] | IsPrime(4^n+33)]; // _Vincenzo Librandi_, Oct 06 2015
%o (PARI) for(n=1, 1e3, if(isprime(4^n+33), print1(n", "))) \\ _Altug Alkan_, Oct 06 2015
%Y Cf. A247953, A253772 (similar sequence).
%K nonn,more
%O 1,2
%A _Robert Price_, Oct 05 2015
%E a(23) derived from A247953 by _Elmo R. Oliveira_, Nov 28 2023