# Catalan's Constant
> [Catalan's constant][catalan-constant].
[Catalan's constant][catalan-constant] `C` (also denoted `K` or `G`) commonly appears in estimates of combinatorial functions and may be defined by the following infinite series
## Usage
```javascript
var CATALAN = require( '@stdlib/constants/float64/catalan' );
```
#### CATALAN
[Catalan's constant][catalan-constant].
```javascript
var bool = ( CATALAN === 0.915965594177219 );
// returns true
```
## Examples
```javascript
var CATALAN = require( '@stdlib/constants/float64/catalan' );
console.log( CATALAN );
// => 0.915965594177219
```
[catalan-constant]: http://en.wikipedia.org/wiki/Catalan%27s_constant
