gammas division Can anyone explain me how to calculate this expression?
$$\frac{\Gamma(n/2)}{\Gamma((n-1)/2)}$$
Thank you, I tried with doble factorial, but don´t know really how to continue.

It's already in the most helpful form. But its large-$n$ asymptotic behaviour is as $\sqrt{n/2}$, by linearizing $\ln\Gamma(z)$ viz.$$\begin{align}\ln\Gamma(n/2)-\ln\Gamma((n-1)/2)&\approx\frac{\ln\Gamma((n+1)/2)-\ln\Gamma((n-1)/2)}{2}\\&=\frac{\ln((n-1)/2)}{2}\\&=\ln\sqrt{(n-1)/2}.\end{align}$$
