摘要: $$ \sum_{a_{1}=1}^{n} \sum_{a_{2}=1}^{n} \ldots \sum_{a_{x}=1}^{n}\left(\prod_{j=1}^{x} a_{j}^{k}\right) f\left(\operatorname{gcd}\left(a_{1}, a_{2}, \ldots, a_{x}\right)\right) \cdot \operatorname{gcd}\left(a_{1}, a_{2}, \ldots, a_{x}\right) $$ 阅读全文
posted @ 2020-08-06 20:17 ljxtt 阅读(123) 评论(0) 推荐(0) 编辑