Let $\mathbf { A } = \left( \begin{array} { c c } 1 & m \\0 & 1\end{array} \right)$

Let $\mathbf { A } = \left( \begin{array} { c c } 1 & m \\0 & 1\end{array} \right)$ Find Aⁿ where n is a positive integer.