The sequence of matrices is defined as given below m(1)=[1]  $\mathrm{m}\left(2\right)=\left[\begin{array}{l}2\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}3\\ 4\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}\hspace{0.25em}5\end{array}\right],\mathrm{m}\left(3\right)=\left[\begin{array}{ccc}6& 7& 8\\ 9& 10& 11\\ 12& 13& 14\end{array}\right]$ and so on then the trace of m (17) is

The first element in m(17) is 1497 and difference of
diagonal elements is 18 then Trace of m(17) is 27897

$trace of m\left(17\right)=\frac{17}{2}\left[2\left(1497\right)+\left(17-1\right)18\right] =27897$