\[\frac{n^{2} - 7n + 4}{n} = \frac{n^{2}}{n} - \frac{7n}{n} + \frac{4}{n} =\]
\[= n - 7 + \frac{4}{n}\]
\[\left( n - 7 + \frac{4}{n} \right) \in Z,\ если\ n =\]
\[= - 4;\ - 2;\ - 1;1;2;4.\]