TeX source:

=\frac{8}{\mathrm{n}^{3}}\left\{\frac{1}{3} \mathrm{n}^{3}+\frac{1}{2} \mathrm{n}^{2}+\frac{2}{12} \mathrm{n}\right\}=\frac{8}{3}+\frac{4}{\mathrm{n}}+\frac{16}{12} \frac{1}{\mathrm{n}^{2}} \longrightarrow \frac{8}{3}