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Primes of the form 2^k + 19.
2

%I #19 Nov 08 2023 08:08:19

%S 23,83,1073741843,5846006549323611672814739330865132078623730171923,

%T 74751027079122046462216955587793573067050655862760405902609490213261724339546970300512875500623813013973275600053770769378323738155015176163371603062328757260320680744718580942157810765768356266003

%N Primes of the form 2^k + 19.

%F a(n) = 2^A057221(n) + 19. - _Elmo R. Oliveira_, Nov 08 2023

%t a = Delete[Union[Flatten[Table[If [PrimeQ[2^n + 19] == True, 2^n + 19, 0], {n, 1, 400}]]], 1]

%o (Magma) [ a: n in [0..750] | IsPrime(a) where a is 2^n+19 ] // _Vincenzo Librandi_, Nov 13 2010

%Y Cf. A000040, A057221.

%K nonn

%O 1,1

%A _Roger L. Bagula_, Mar 02 2005