Find the law: 3 / 4, 1 / 2, 1 / 3, 2 / 9, (), ()

Find the law: 3 / 4, 1 / 2, 1 / 3, 2 / 9, (), ()

3 / 4, 1 / 2, 1 / 3, 2 / 9, (4 / 27), (8 / 81)
An equal ratio sequence with a common ratio of 2 / 3. Multiplying the former by 2 / 3 equals the latter