Least m such that 1 + prime(n)*2^m is a prime, or -1 if no such m exists.

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =1a(5) =2a(6) =3a(7) =6a(8) =1a(9) =1a(10) =8a(11) =2a(12) =1a(13) =2a(14) =583a(15) =1a(16) =5a(17) =4a(18) =2a(19) =3a(20) =2a(21) =2a(22) =1a(23) =1a(24) =2a(25) =3a(26) =16a(27) =3a(28) =6a(29) =1