rt
(123−1+133−1+143−1......11003−1\frac{1}{2^3-1}+\frac{1}{3^3-1}+\frac{1}{4^3-1}......\frac{1}{100^3-1}23−11+33−11+43−11......1003−11)×53\times5^3×53
求助!