Least k such that A000668(n) + k is prime, where A000668(n) is the n-th Mersenne prime.

Terms

a(0) =2a(1) =4a(2) =6a(3) =4a(4) =18a(5) =30a(6) =22a(7) =12a(8) =16a(9) =30a(10) =40a(11) =30a(12) =888a(13) =486a(14) =2056a(15) =696a(16) =310a(17) =718a(18) =4692a(19) =1600a(20) =2788a(21) =4290a(22) =4326a(23) =4150a(24) =18088a(25) =22096a(26) =16342a(27) =72816a(28) =181720a(29) =4200