Contact us
Choose a category below so we can get back to you as quickly as possible.
分子1,2,3,4,…… 分母1×3,3×5,5×7,7×9,…… 符號+-+-+-…… 所以第n個是(-1)的n次方×n/[(2n-1)(2n+1)]
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.