Numbers k such that 2^k + 2*k + 1 is prime.

Terms

a(0) =0a(1) =1a(2) =5a(3) =13a(4) =65a(5) =85a(6) =229a(7) =2005a(8) =3875a(9) =3919a(10) =5417a(11) =8819a(12) =11899a(13) =16668a(14) =19445a(15) =28242a(16) =33407a(17) =37918a(18) =40594a(19) =141251