Primes of the form 5+3*2^k.

Terms

a(0) =11a(1) =17a(2) =29a(3) =53a(4) =101a(5) =197a(6) =389a(7) =773a(8) =49157a(9) =196613a(10) =1572869a(11) =12582917a(12) =50331653a(13) =402653189a(14) =1610612741a(15) =12884901893a(16) =824633720837