# Function catalan The Catalan Numbers enumerate combinatorial structures of many different types. catalan only takes integer arguments. The following condition must be enforced: n >= 0 ## Syntax ```js math.catalan(n) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `n` | Number | BigNumber | nth Catalan number ### Returns Type | Description ---- | ----------- Number | BigNumber | Cn(n) ### Throws Type | Description ---- | ----------- ## Examples ```js math.catalan(3) // returns 5 math.catalan(8) // returns 1430 ``` ## See also [bellNumbers](bellNumbers.md)