Function perm

pub fn perm(base: u64, numbers: u64) -> Result<i64, EcoString>

Calculates a permutation.

Returns the k-permutation of n, or the number of ways to choose k items from a set of n with regard to order.

$ "perm"(n, k) &= n!/((n - k)!) \
  "perm"(5, 3) &= #calc.perm(5, 3) $