Primes of the form 2^n + 39.

Terms

a(0) =41a(1) =43a(2) =47a(3) =71a(4) =103a(5) =167a(6) =1063a(7) =2087a(8) =8231a(9) =131111a(10) =536870951a(11) =8589934631a(12) =549755813927