A163115 Primes of the form 2^n + 2*n + 1.

2, 5, 43, 8219, 36893488147419103363, 38685626227668133590597803, 862718293348820473429344482784628181556388621521298319395315527975371

Offset: 1

Author

Juri-Stepan Gerasimov, Jul 21 2009

Keywords

• nonn

Comments

The corresponding values of n, i.e., 0, 1, 5, 13, 65, 85, 229, ... are of the form A192764() - 1. - Juri-Stepan Gerasimov, Jul 25 2011

The next term, a(8), has 604 digits. - Harvey P. Dale, Dec 17 2013

Examples

			a(1) = 2^0 + 2*0 + 1 = 2.
a(2) = 2^1 + 2*1 + 1 = 5.
a(3) = 2^5 + 2*5 + 1 = 43.
a(4) = 2^13 + 2*13 + 1 = 8219.
		

Programs

Mathematica

Select[Table[2^n+2n+1,{n,0,300}],PrimeQ] (* Harvey P. Dale, Dec 17 2013 *)

Extensions

13 removed, 3 terms added by R. J. Mathar, Jul 27 2009