Bài 1:
Cho $u_{n}: \begin{cases} & u_{1}=2 \\ & u_{n+1}=\frac{u{_{n}}^{2}+2015u_{n}}{2016} \end{cases}$
Tìm $\lim\sum_{i=1}^{n}\frac{u_{i}}{u_{i+1}-1}$
Bài 2:
$u_{n}: \begin{cases} & u_{0}=\frac{1}{2}\\& u_{k}=u_{k-1}+\frac{1}{n}u_{k-1}^{2} \end{cases}$
Tìm $\lim u_{n}$