Which state of triply ionised Baryllium (Be⁺⁺⁺) has the same orbital radius as that of the ground state of hydrogen

Radius of n^th orbit for any hydrogen like atom 
${\mathrm{r}}_{\mathrm{n}}={\mathrm{r}}_0\left(\frac{{\mathrm{n}}^2}{\mathrm{Z}}\right)\left({\mathrm{r}}_0=\text{ radius of first orbit of }{\mathrm{H}}_2-\right.\mathrm{atom})$
$\text{ If }{\mathrm{r}}_{\mathrm{n}}={\mathrm{r}}_0\Rightarrow \mathrm{n}=\sqrt{\mathrm{Z}}.\text{ For }{\mathrm{Be}}^{+++},\mathrm{Z}=4\Rightarrow \mathrm{n}=2$