pub fn upper_central_series(
degree: usize,
gens: &[Perm],
cap: usize,
) -> Option<Vec<u128>>Expand description
The orders [|Z₀|, |Z₁|, …] of the upper central series, up to the hypercentre. Z₀ = {id} and
Z_{i+1} = { g : [g, x] ∈ Z_i for all x } (the preimage of the centre of G/Z_i). The series ascends
to |G| iff G is nilpotent. None when |G| > cap.