The Möbius function is a number theoretic function defined by μ(n) congruent {0 | if n has one or more repeated prime factors 1 | if n = 1 (-1)^k | if n is a product of k distinct primes, auto right match so μ(n)!=0 indicates that n is squarefree. The first few values of μ(n) are therefore 1, -1, -1, 0, -1, 1, -1, 0, 0, 1, -1, 0, ... (OEIS A008683). Similarly, the first few values of left bracketing bar μ(n) right bracketing bar for n = 1, 2, ... are 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, ... (OEIS A008966).

Braun's conjecture | Dirichlet generating function | Mertens function | Möbius inversion formula | Möbius periodic function | Möbius transform | prime zeta function | Riemann function | squarefree