Even term coefficient, that is, the degree of x is even.

Let x= 1, then the odd term coefficient+even term coefficient = (1+1+) 4 = 256.

Let x=- 1, then even term coefficient-odd term coefficient = (1-1+1) 4 = 0.

Up-down type

2 times the odd term coefficient =256

The sum of odd-numbered coefficients is 128.

The answer is 128.