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

Terms

a(0) =1a(1) =2a(2) =2a(3) =14a(4) =12a(5) =8a(6) =18a(7) =18a(8) =30a(9) =20a(10) =170a(11) =24a(12) =114a(13) =56a(14) =156a(15) =2510a(16) =1824a(17) =12a(18) =3980a(19) =3630a(20) =16902a(21) =284a(22) =7712a(23) =20022a(24) =12930a(25) =9698a(26) =16232a(27) =1058a(28) =256016a(29) =23712