Find the missing number :

$34, 18, 10, 6, 4, ?$

Find the missing number :

$2, 5, 9, 19, 37, ?$

Find the missing number.

$14, 50, 110, 200, ?$

Find the missing number.

$1, 2, 5, 12, 27, ?$

Find the missing number.

$17, 19, 23, 29, 31, ?$

Find the missing number.

$3, 12, 27, 48, 75, ?$

Find the missing number.

$463, 547, 379, 715, ?$

Find the missing number :

$11, 12, 17, 18, 23, 24, ?$

Find the missing number:

$2, 6, 12, 20, 30, 42, ?$