Numbers k for which 4^k - 27 is prime.

Terms

a(0) =3a(1) =4a(2) =5a(3) =10a(4) =11a(5) =13a(6) =25a(7) =28a(8) =29a(9) =65a(10) =70a(11) =115a(12) =305a(13) =515a(14) =2029a(15) =2393a(16) =2605a(17) =3530a(18) =4036a(19) =4750a(20) =10288a(21) =11048a(22) =11596a(23) =29359a(24) =32123a(25) =47371