Contact us
Choose a category below so we can get back to you as quickly as possible.
32²;+32²;+……+99²;=(1²;+2²;+……+99²;)-(1²;+2²;+……+31²;)=99*100*199/6-31*32*63/6“利用公式1²;+2²;+……+n²;=n(n+1)(2n+1)/6“=328350-10416=31…
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.