\[\boxed{\mathbf{17}\mathbf{.}}\]
\[\lim_{n \rightarrow \infty}x^{n} = 0.\]
\[1)\ \lim_{n \rightarrow \infty}\frac{1}{4^{n}} = \lim_{n \rightarrow \infty}\left( \frac{1}{4} \right)^{n} = 0.\]
\[2)\ \lim_{n \rightarrow \infty}(0,2)^{n} = 0.\]
\[3)\ \lim_{n \rightarrow \infty}\left( 1 + \frac{1}{7^{n}} \right) =\]
\[= \lim_{n \rightarrow \infty}\left( 1 + \left( \frac{1}{7} \right)^{n} \right) = 1 + 0 = 1.\]
\[4)\ \lim_{n \rightarrow \infty}\left( \left( \frac{3}{5} \right)^{n} - 2 \right) =\]
\[= 0 - 2 = - 2.\]