Numbers k such that 3^k (mod 2^k) is prime.

Terms

a(0) =3a(1) =5a(2) =7a(3) =9a(4) =11a(5) =20a(6) =28a(7) =62a(8) =161a(9) =204a(10) =471a(11) =505a(12) =881a(13) =1810a(14) =1812a(15) =2506a(16) =3321a(17) =6809a(18) =9272a(19) =15131a(20) =17449a(21) =25250a(22) =27989a(23) =36082a(24) =53309a(25) =64970a(26) =66354a(27) =69646a(28) =96080a(29) =176059