求如下柿子各项系数
∑i=0D(Di)(x+1)i(x−1)D−i(2i−D)n\sum_{i=0}^D\dbinom{D}{i}\left(x+1\right)^i\left(x-1\right)^{D-i}(2i-D)^n∑i=0D(iD)(x+1)i(x−1)D−i(2i−D)n
