Primes of the form 3*2^n - 2*n - 1.

Terms

a(0) =2a(1) =3a(2) =7a(3) =17a(4) =179a(5) =751a(6) =6121a(7) =12263a(8) =49123a(9) =393181a(10) =50331599a(11) =201326539