In each of the following number series, a wrong number is given. Find out that number.
346, 342, 333, 308, 259, 178
The series follows the following pattern:
346 - 22 = 342
342- 32 = 333
333 - 52 = 308
308 - 72 = 259
259 - 112 = 138
∴ The wrong term in the series is 178.