A156973 Primes of the form 2^k + 17.

19, 8209, 2097169, 8589934609, 2417851639229258349412369, 680564733841876926926749214863536422929, 62165404551223330269422781018352605012557018849668464680057997111644937126566671941649

Offset: 1

Author

Edwin Dyke (ed.dyke(AT)btinternet.com), Feb 19 2009

Keywords

• nonn

Examples

			19 = 2^1 + 17 is in the sequence;
8209 = 2^13 + 17 is in the sequence.
		

Crossrefs

Cf. A000040, A057200, A057733 (2^k + 3), A123250 (2^k + 5), A104066 (2^k + 7), A156940 (2^k + 11), A104067 (2^k + 13).

Programs

Magma

[ a: n in [1..400] | IsPrime(a) where a is 2^n+17 ]; // Vincenzo Librandi, Nov 27 2010

Mathematica

Delete[Union[Table[If[PrimeQ[2^n + 17], 2^n + 17, 0], {n, 1, 300}]],1]

Formula

a(n) = 2^A057200(n) + 17. - Elmo R. Oliveira, Nov 08 2023

Extensions

a(7) from Vincenzo Librandi, Apr 29 2010