> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/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/sidef-lang/programming_tasks/a/amicable_pairs.md).

# Amicable pairs

```ruby
func propdivsum(n) {
    n.sigma - n
}

for i in (1..20000) {
    var j = propdivsum(i)
    say "#{i} #{j}" if (j>i && i==propdivsum(j))
}
```

## Output:

```
220 284
1184 1210
2620 2924
5020 5564
6232 6368
10744 10856
12285 14595
17296 18416
```