Least k such that k*(Mersenne_prime(n)^2) + 1 is prime.

Terms

a(0) =2a(1) =4a(2) =16a(3) =12a(4) =22a(5) =28a(6) =30a(7) =22a(8) =138a(9) =12a(10) =102a(11) =180a(12) =426a(13) =1444a(14) =9502a(15) =6568a(16) =2212a(17) =5380a(18) =9942a(19) =3034a(20) =24222a(21) =31530a(22) =2962a(23) =7848a(24) =93280a(25) =3718