Discuss the convergence of the sequence $(a_{n})$, where $a_{n}:=1+\frac{1}{2^2}+\frac{1}{3^2}+ \dots +\frac{1}{n^2}$. How to show this
Does $\sum\limits_{k=1}^n 1 / k ^ 2$ converge when $n\rightarrow\infty$?