---
tag: 0VQQCVG8WA
kind: concept
name: Combinations with repetition
msc: [05A10]
sources:
  - url: https://en.wikipedia.org/wiki/Multiset
    locator: Counting multisets
---

## Summary

A combination with repetition is a selection of $k$ elements from a set in which the order does not matter and elements can repeat. Such selections are multisets of size $k$, and stars and bars counts them. The node [[combinations with repetition|0YEQG3VBYC]] gives the precise definition.