> 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/g/giuga_numbers.md).

# Giuga numbers

```perl
my @primes = (3..60).grep: &is-prime;

print 'First four Giuga numbers: ';

put sort flat (2..4).map: -> $c {
    @primes.combinations($c).map: {
        my $n = [×] 2,|$_;
        $n if all .map: { ($n / $_ - 1) %% $_ };
    }
}
```

#### Output:

```
First 4 Giuga numbers: 30 858 1722 66198
```