Definition:Catalan Number

Definition
The Catalan Numbers $C_n$ are a sequence of natural numbers defined by:


 * $C_n = \dfrac 1 {n + 1} \dbinom {2 n} n $

The values of the first Catalan numbers are:


 * $1, 1, 2, 5, 14, 42, 132, 429, 1430, 4862, \ldots $