Numbers k for which (2^k + 1)/F is prime where F is a Fermat number.

Terms

a(0) =3a(1) =5a(2) =6a(3) =7a(4) =11a(5) =12a(6) =13a(7) =17a(8) =19a(9) =20a(10) =23a(11) =28a(12) =31a(13) =40a(14) =43a(15) =61a(16) =79a(17) =92a(18) =96a(19) =101a(20) =104a(21) =127a(22) =148a(23) =167a(24) =191a(25) =199a(26) =313a(27) =347a(28) =356a(29) =596