Answer
Converges to $0$.
Work Step by Step
$\lim\limits_{n \to \infty}a_{n}=\lim\limits_{n \to \infty}\frac{tan^{-1}n}{n}$
$=\frac{\lim\limits_{n \to \infty}tan^{-1}n}{\lim\limits_{n \to \infty}n}$
$=\frac{\pi/2}{\infty}$
$=0$
The given sequence converges to $0$.