Numbers k such that 391*2^k+1 is prime.

Terms

a(0) =4a(1) =20a(2) =28a(3) =40a(4) =88a(5) =92a(6) =328a(7) =1052a(8) =1420a(9) =2888a(10) =3944a(11) =5888a(12) =22544a(13) =154912a(14) =716668a(15) =2971600a(16) =3693728