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%I #20 Nov 08 2023 07:41:22
%S 11,13,17,41,73,137,521,1033,262153,8388617,1073741833,137438953481,
%T 140737488355337,144115188075855881,73786976294838206473,
%U 4835703278458516698824713,39614081257132168796771975177
%N Primes of the form 2^k + 9.
%F a(n) = 2^A057196(n) + 9. - _Elmo R. Oliveira_, Nov 08 2023
%t a = Delete[Union[Flatten[Table[If [PrimeQ[2^n + 9] == True, 2^ n + 9, 0], {n, 1, 400}]]], 1]
%t Select[2^Range[0,100]+9,PrimeQ] (* _Harvey P. Dale_, Mar 11 2023 *)
%o (Magma) [a: n in [0..250] | IsPrime(a) where a is 2^n+9]; // _Vincenzo Librandi_, Jan 26 2011
%Y Cf. A000040, A057196 (numbers k such that 2^k + 9 is prime). [From _Klaus Brockhaus_, Mar 14 2009]
%K nonn
%O 1,1
%A _Roger L. Bagula_, Mar 02 2005
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