11, 18, 29, 42, 59, 80, 101

The series is + 7, + 11, + 13, + 17, + 19, + 23
11 + 7 = 18, 18 + 11 = 29, 29 + 13 = 42, 42 + 17 = 59, 59 + 19 = 78, 78 + 23 = 101
The wrong number is 34650; 17325 x 3 = 51975