rt，尽量用一些简单的方法吧
∑i=010C10i(∑j=010−iC10−ij×2i×2i+j)\sum_{i=0}^{10}C_{10}^{i}(\sum_{j=0}^{10-i}C_{10-i}^{j}\times 2^{i}\times 2^{i+j})∑i=010C10i(∑j=010−iC10−ij×2i×2i+j)
