A105307 Log base 2 of the number of divisors of Fibonacci[n] if that number is a power of 2, else -1.

0, 0, 1, 1, 1, 2, 1, 2, 2, 2, 1, -1, 1, 2, 3, 3, 1, 4, 2, 4, 3, 2, 1, -1, -1, 2, 4, 4, 1, 6, 2, 4, 3, 2, 3, -1, 3, 3, 3, 6, 2, 6, 1, 5, 5, 3, 1, -1, 3, -1, 3, 4, 2, 7, 4, -1, 5, 3, 2, -1, 2, 3, 5, 6, 3, 6, 3, 5, 5, 7, 2, -1, 2, 4, -1, 5, 4, 7, 2, 9, 7, 3, 1, -1, 4, 3, 4, 9, 2, 11, -1, 6, 4, 2, 6, -1, 4, 5, 6, -1, 2, 7, 3, 7, 7, 3, 2, -1, 2, -1, 5, -1, 2, 9, 4, 6, 6, 5, 3