The series should increase by 7 each time: 8+7=15, 15+7=22, 22+7=29, 29+7=36, 36+7=43, 43+7=50. But the given series has 34 instead of 36 between 29 and 43. Checking: 29+7=36, but the series shows 34. So 34 is the wrong number. The sequence should be: 8, 15, 22, 29, 36, 43, 50.