d
$\begin{gathered}
\,n\, = \,\,3\,;\,\,\,\,a\,\, = \,\,{2^{3 - 1}}\, - \,\,{2^{\frac{{3 - 1}}{2}}}\,\, = \,\,\,{2^2} - {2^1}\,\, = \,\,2 \hfill \\
m\, = \,\,{2^{\frac{{3 - 1}}{2}}}\,\, = \,\,2 \hfill \\
(a + m)\,\, = \,\,2\,\, + \,\,2\,\,\, = \,\,4 \hfill \\
\end{gathered} $