> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/perl6-rosettacode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/perl6-rosettacode/programming_tasks/c/catalan_numbers.md).

# Catalan numbers

The recursive formulas are easily written into a constant array, either:

```perl
constant Catalan = 1, { [+] @_ Z* @_.reverse } ... *;
```

or

```perl
constant Catalan = 1, |[\*] (2, 6 ... *) Z/ 2 .. *;


# In both cases, the sixteen first values can be seen with:
.say for Catalan[^16];
```

#### Output:

```
1
1
2
5
14
42
132
429
1430
4862
16796
58786
208012
742900
2674440
```