nCk ( n k -- nCk )


Vocabulary
math.combinatorics

Inputs and outputs
na non-negative integer
ka non-negative integer
nCkan integer


Word description
Outputs the total number of unique combinations of size k (order does not matter) that can be taken from a set of size n. Commonly written as "n choose k".

Examples
USING: math.combinatorics prettyprint ; 10 4 nCk .
210


Definition