Find the missing number in the following series. 2/3, 4/7, ?, 11/21, 16/31

The missing number (?) in the following series is : 3, 7, 15, 31, 63, ?

Find the missing number in the given series 3, 4, 7, 11, 18, 29, ?

Find the missing number in the following number series. 3, 5, 8, 10, ?, 15, 18, 20

Find the missing number in the following – 2, 3, 4, 6, 6, 9, 8, 12, 10, ............, 12, 18, 14, 21, 16, 24

Find the missing number in the given series 4, -8, 16, -32, 64, ?