A173063 Numbers n such that 2^n + n - 1 is a prime.

1, 2, 4, 8, 10, 16, 86, 344, 406, 424, 2324, 6358, 11026, 11804, 48926, 266744

Offset: 1

Author

Vincenzo Librandi, Feb 09 2010

Keywords

• nonn

Comments

The associated prime list is 2, 5, 19, 263, 1033, 65551, 77371252455336267181195349 etc.

a(17) > 335000. - Giovanni Resta, Mar 26 2014

Examples

			For n=2, 2^2+2-1=5 is prime. For n=4, 2^4+4-1=19 is prime.
		

Programs

Mathematica

fQ[n_] := PrimeQ[ 2^n + n - 1]; k = 1; lst = {}; While[k < 35000, If[ fQ@k, AppendTo[ lst, k]; Print@k]; k ++ ] (* Robert G. Wilson v, Feb 26 2010 *)

Extensions

Definition corrected, leading 1 inserted, 5 terms appended - R. J. Mathar, Feb 13 2010

a(12) - a(15) from Robert G. Wilson v, Feb 26 2010

a(16) from Giovanni Resta, Mar 26 2014