The series has two interleaved sequences. Odd positions (1st, 3rd, 5th): 4, 6, 8 (increasing by 2). Even positions (2nd, 4th, 6th): 22, 19, 17 (should decrease by 2, giving 22, 20, 18). The number 22 breaks this pattern - it should be 20 (4-3=1, 6-3=3). So 22 is the wrong number.