---
tag: 0FANE7P0DY
kind: concept
name: Möbius function
msc: [11A25]
sources:
  - url: https://en.wikipedia.org/wiki/M%C3%B6bius_function
    locator: lead section
same_as:
  wikidata: Q205243
  wikipedia: Möbius function
---

## Summary

The Möbius function $\mu$ is an arithmetic function that is $0$ on integers with a square factor greater than $1$.
On a squarefree integer, its value $1$ or $-1$ depends on the parity of the number of prime factors.
The [[definition of the Möbius function|0C8QENHYZW]] gives the precise form.