Möbius function
= Möbius function
{wiki}
The Möbius function is $\mu(1)=1$, is zero on integers divisible by a prime square, and is $(-1)^r$ on products of $r$ distinct primes.
= Möbius function
{wiki}
The Möbius function is $\mu(1)=1$, is zero on integers divisible by a prime square, and is $(-1)^r$ on products of $r$ distinct primes.