Numbers k such that 2*6^k - 1 is prime.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =12a(6) =16a(7) =26a(8) =27a(9) =36a(10) =40a(11) =45a(12) =49a(13) =52a(14) =53a(15) =75a(16) =140a(17) =150a(18) =167a(19) =245a(20) =250a(21) =755a(22) =785a(23) =825a(24) =970a(25) =1235a(26) =1289a(27) =1477a(28) =1739a(29) =1872