\begin{equation*}
\mu = \frac{r}{2}2 = r
\end{equation*}
\begin{equation*}
\sigma^2 = \frac{r}{2}2^2 = 2r
\end{equation*}
\begin{equation*}
\gamma_1 = \frac{2}{\sqrt{\frac{r}{2}}} = \frac{2^{3/2}}{\sqrt{r}}
\end{equation*}
\begin{equation*}
\gamma_2 = \frac{6}{\frac{r}{2}} + 3 = \frac{12}{r} + 3
\end{equation*}