题面\\ 求∑i=1n∑j=1iphi(j)×⌊ij⌋求\sum_{i=1}^n \sum_{j=1}^{i} phi(j) \times \lfloor \frac{i}{j} \rfloor \\求∑i=1n∑j=1iphi(j)×⌊ji⌋ 设g(n)=∑i=1n∑j=1iphi(j)×⌊ij⌋设g(n)=\sum_{i=1}^n \sum_{j=1}^{i} phi(j) \times \lfloor \frac{i}{j} \rfloor \\设g(n)=∑i=1n∑j=1iphi(j)×⌊ji⌋ 设h(n)=g(n)−g(n−1)=∑i=1nphi(i)×⌊ni⌋设h(n...