The next number in the series is always found by dividing the previous number by the number before it. So you calculate the number at position 3 by dividing the number at position 2 by the number at position 1.
22 / 11 = 2
2 / 22 = 1/11
1/11 / 2 = 1/22
1/22 / 1/11 = 1/2
1/2 / 1/22 = 11
11 / 1/2 = 22