---
tag: 07NN4VNYWM
kind: concept
name: Liouville function
msc: [11A25]
sources:
  - url: https://en.wikipedia.org/wiki/Liouville_function
    locator: lead section
same_as:
  wikidata: Q385019
  wikipedia: Liouville function
---

## Summary

The Liouville function $\lambda(n)$ is $1$ or $-1$, by the parity of the number of prime factors of $n$ counted with multiplicity.
The [[definition of the Liouville function|08RQAPXF1T]] gives the precise form.