Möbius Function/Examples/2

Example of Möbius Function

For $n \in \Z_{>0}$, let $\map \mu n$ denote the Möbius function of $n$.

Then:

$\map \mu 2 = -1$


Proof

\(\ds 2\) \(=\) \(\ds 2^1\) Note that $2$ is prime
\(\ds \leadsto \ \ \) \(\ds \map \mu 2\) \(=\) \(\ds \paren {-1}^1\) Definition of Möbius Function
\(\ds \) \(=\) \(\ds -1\)

$\blacksquare$


Sources

  • 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): Möbius function