> 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/t/thue-morse.md).

# Thue-Morse

```ruby
func recmap(repeat, seed, transform, callback) {
    func (repeat, seed) {
        callback(seed)
        repeat > 0 && __FUNC__(repeat-1, transform(seed))
    }(repeat, seed)
}
 
recmap(6, "0", {|s| s + s.tr('01', '10') }, { .say })
```

#### Output:

```
0
01
0110
01101001
0110100110010110
01101001100101101001011001101001
0110100110010110100101100110100110010110011010010110100110010110
```