A104068 Primes of the form 2^k + 19.

23, 83, 1073741843, 5846006549323611672814739330865132078623730171923, 74751027079122046462216955587793573067050655862760405902609490213261724339546970300512875500623813013973275600053770769378323738155015176163371603062328757260320680744718580942157810765768356266003

Offset: 1

Author

Roger L. Bagula, Mar 02 2005

Keywords

• nonn

Crossrefs

Cf. A000040, A057221.

Programs

Magma

[ a: n in [0..750] | IsPrime(a) where a is 2^n+19 ] // Vincenzo Librandi, Nov 13 2010

Mathematica

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

Formula

a(n) = 2^A057221(n) + 19. - Elmo R. Oliveira, Nov 08 2023