### Atom - `œ?`

- Permutation At Index

Tags: `miscellaneous` , `array` , `combinatorics`

##### Arity: dyadic

This atom is dyadic, which means it takes two arguments.

##### Functionality

Return the `x`

^{th} permutation of `y`

.

##### Details

`x œ? y`

is equivalent to `y Œ! x ị`

(but much more efficient, as it does not have to generate all `len(y)!`

permutations).

##### Synonyms

This atom should work roughly the same way as or very similarly in concept to the following code snippets (some edge case exceptions may exist):

`ịŒ!}¥`