Numbers k such that 2^k - 9 is prime.

Terms

a(0) =4a(1) =5a(2) =9a(3) =11a(4) =17a(5) =21a(6) =33a(7) =125a(8) =141a(9) =243a(10) =251a(11) =285a(12) =321a(13) =537a(14) =563a(15) =699a(16) =729a(17) =2841a(18) =3365a(19) =8451a(20) =8577a(21) =9699a(22) =9725a(23) =21011a(24) =22689a(25) =33921a(26) =51761a(27) =655845a(28) =676761a(29) =3480081