9, 19, 40, 83, 170, 340

9 × 2 + 1 = 18 + 1 = 19 19 × 2 + 2 = 38 + 2 = 40 40 × 2 + 3 = 80 + 3 = 83 83 × 2 + 4 = 166 + 4 = 170

Therefore, the number 340 is wrong in the series.