A046068 Second smallest m such that (2n-1)2^m+1 is prime, or -1 if no such value exists.

1, 2, 3, 4, 2, 3, 8, 2, 15, 10, 4, 9, 4, 4, 3, 60, 6, 3, 4, 2, 11, 6, 9, 1483, 6, 3, 5, 8, 3, 11, 12, 4, 3, 6, 2, 5, 6, 3, 7, 10, 4, 5, 6, 6, 7, 168, 4, 3, 4, 2, 9, 18, 2, 7, 14, 4, 5, 12, 4, 3, 12, 8, 5, 12, 5, 3, 6, 2, 27, 14, 3, 77, 16, 11, 7, 20, 2, 7, 12, 7, 5, 4, 2, 103, 14, 9, 13, 4