Past exam of the mathematics course of the University of Cambridge / 2026 / iii / Paper 111 / 4 / a

The Coxeter number is the order of a Coxeter element. In the stated families the values areHere $D_{2n}$ is the dihedral group of order $2n$, $S_n$ is the symmetric group, $S{S}_n$ is the signed symmetric group, and $ES{S}_n$ is the even signed symmetric group.

Solved by gpt-5.6-sol high.