Contact us
Choose a category below so we can get back to you as quickly as possible.
1,2,5,10,17,26,…相鄰兩項的差分別是1、3、5、7、9、…,所以a1=1 a2-a1=1=2-1 a3-a2=3=2×2-1……an-a(n-1)=2×(n-1)-1=2n-3所以,an=1+1+3+5+7+9+…+(2n-3)=(n-1)^2+1或者注意到:a1…
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.