# 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
```


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