begin{center}
{Ctextsubscript{n}}=$frac{(2n)!}{(n+1)!n!}$
hspace{1.5cm}
{Ctextsubscript{n}}=$frac{1}{n+1}$$binom{2n}{n}$
hspace{1.5cm}
{Ctextsubscript{n}}=$binom{2n}{n}$-$binom{2n}{n+1}$
end{center}