Numbers k such that 19*2^k - 1 is prime.

Terms

a(0) =1a(1) =3a(2) =5a(3) =21a(4) =41a(5) =49a(6) =89a(7) =133a(8) =141a(9) =165a(10) =189a(11) =293a(12) =305a(13) =395a(14) =651a(15) =665a(16) =771a(17) =801a(18) =923a(19) =953a(20) =3689a(21) =5315a(22) =6989a(23) =15641a(24) =48819a(25) =78389a(26) =134053a(27) =167843a(28) =181395a(29) =311091