Evaluate the limit:
$$\ell= \lim_{n \rightarrow +\infty} \frac{1}{n^2} \sum_{m=1}^{n} n \pmod m$$
Welcome to mathimatikoi.org forum; Hope you enjoy you stay here!
Arithmotheoretic limit
Arithmotheoretic limit
$\displaystyle \sum_{n=1}^{\infty}\frac{1}{n^s}= \prod_{p \; \text{prime}}\frac{1}{1-p^{-s}}$