MathDB
ICMC 2018/19 Round 2, Problem 2

Source: Imperial College Mathematics Competition 2018/19 - Round 2

August 7, 2020
college contests

Problem Statement

In the symmetric group Sn (n3)S_n\ (n \geq 3), let Ga,bG_{a,b} be the subgroup generated by the 2-cycle (a b)(a\ b) and the n-cycle (1 2  n)(1\ 2\ \cdots\ n). Find the index Sn:Ga,b\left|S_n : G_{a,b}\right|.