Contact us
Choose a category below so we can get back to you as quickly as possible.
0+2+4+6+...+2(n-1) =2(n-1)*n/2 =n(n-1) an=1+n(n-1) =n²-n+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.