MathDB
Simple Combinatorics on seating in a circle

Source:

August 11, 2019
Circular permutationsgeometrygeometric transformationrotation

Problem Statement

Five persons wearing badges with numbers 1,2,3,4,51, 2, 3, 4, 5 are seated on 55 chairs around a circular table. In how many ways can they be seated so that no two persons whose badges have consecutive numbers are seated next to each other? (Two arrangements obtained by rotation around the table are considered different)