Numbers k such that 4^k + 7 is prime.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =8a(6) =9a(7) =10a(8) =14a(9) =15a(10) =19a(11) =22a(12) =39a(13) =44a(14) =49a(15) =63a(16) =80a(17) =87a(18) =102a(19) =107a(20) =294a(21) =305a(22) =399a(23) =463a(24) =595a(25) =599a(26) =903a(27) =944a(28) =1324a(29) =1727