Question

一道数学题,有点难

Answer 1

an+1=an+an/(n+1)(n+1)*a(n+1)=(n+2)*ana(n+1)/an=(n+2)/(n+1)an/a(n-1)=(n+1)/na(n-1)/a(n-2)=n/(n-1)a2/a1=3/2所有项相乘,an/a1=(n+1)/2an=(n+1)/2*a1=(n+1)/2an=(n+1)/2 O(∩_∩)O