Numbers k such that 81*2^k+1 is prime.

Terms

a(0) =1a(1) =4a(2) =5a(3) =7a(4) =12a(5) =15a(6) =16a(7) =21a(8) =25a(9) =27a(10) =32a(11) =35a(12) =36a(13) =39a(14) =48a(15) =89a(16) =104a(17) =121a(18) =125a(19) =148a(20) =152a(21) =267a(22) =271a(23) =277a(24) =296a(25) =324a(26) =344a(27) =396a(28) =421a(29) =436