Least number k such that k*n+1 is a prime dividing 2^n-1.

Terms

a(0) =1a(1) =2a(2) =1a(3) =6a(4) =1a(5) =18a(6) =2a(7) =8a(8) =1a(9) =2a(10) =1a(11) =630a(12) =3a(13) =2a(14) =1a(15) =7710a(16) =1a(17) =27594a(18) =2a(19) =6a(20) =1a(21) =2a(22) =10a(23) =24a(24) =105a(25) =9728a(26) =1a(27) =8a(28) =1a(29) =69273666