Solution
= Solution
Since $D^6=\operatorname{diag}(1,4^6)=\operatorname{diag}(1,4096)$,
$$
A^6=\frac13\begin{pmatrix}2&4096\\-1&4096\end{pmatrix}
\begin{pmatrix}1&-1\\1&2\end{pmatrix}
=\boxed{\begin{pmatrix}1366&2730\\1365&2731\end{pmatrix}}.
$$
= Solution
Since $D^6=\operatorname{diag}(1,4^6)=\operatorname{diag}(1,4096)$,
$$
A^6=\frac13\begin{pmatrix}2&4096\\-1&4096\end{pmatrix}
\begin{pmatrix}1&-1\\1&2\end{pmatrix}
=\boxed{\begin{pmatrix}1366&2730\\1365&2731\end{pmatrix}}.
$$