Least k such that Mersenne-prime(n)*2^k+1 is prime (A000668(n)*2^k+1).

Terms

a(0) =1a(1) =2a(2) =8a(3) =2a(4) =12a(5) =864a(6) =4a(7) =10a(8) =8a(9) =72a(10) =18a(11) =38a(12) =2144a(13) =178a(14) =472a(15) =974a(16) =2200a(17) =8128a(18) =4580a(19) =822a(20) =3600a(21) =4100