Möbius inversion formula (source code)

= Möbius inversion formula
{c}
{wiki}

If arithmetic functions $f,g$ satisfy
$$
g(n)=\sum_{d\mid n}f(d),
$$
then
$$
f(n)=\sum_{d\mid n}\mu(d)g(n/d).
$$

= Möbius inversion
{c}
{synonym}