Mobius

Mobius

形式一

\[
f\left(n\right) = \sum_{d|n}g\left(d\right) \\
g\left(n\right) = \sum_{d|n}\mu\left(d\right)f\left(\frac{n}{d}\right)
\]

形式二

\[
f\left(n\right) = \sum_{n|d}g\left(d\right) \\
g\left(n\right) = \sum_{n|d}\mu\left(\frac{d}{n}\right)f\left(d\right)
\]