Multinomial coefficien¶
\[\binom{n}{x_1 \cdots x_K} \triangleq \frac{n!}{x_1! x_2! \cdots x_K!}\]
It computes the number of ways we can divide a set of size \(n = \sum_{k-1}^K x_k\) into subsets with size \(x_1\) up to \(x_k\)
It computes the number of ways we can divide a set of size \(n = \sum_{k-1}^K x_k\) into subsets with size \(x_1\) up to \(x_k\)