pub fn mobius_number(degree: usize, gens: &[Perm], cap: usize) -> Option<i128>Expand description
The Möbius number μ(1, G) of the subgroup lattice of G = ⟨gens⟩ — the value of the lattice’s
Möbius function from the trivial subgroup to the whole group. A classical invariant: for a cyclic group
μ(1, Cₙ) is the number-theoretic Möbius function μ(n), and in general it drives the group’s Eulerian
(probabilistic-zeta) function. None when |G| > cap.