Arrange on a circle all composite positive integers
Source: Tuymaada 2008, Senior League, First Day, Problem 2.
July 20, 2008
AMCUSA(J)MOUSAMOnumber theoryprime numbersnumber theory unsolved
Problem Statement
Is it possible to arrange on a circle all composite positive integers not exceeding , so that no two neighbouring numbers are coprime?
Author: L. Emelyanov
[hide="Tuymaada 2008, Junior League, First Day, Problem 2."]Prove that all composite positive integers not exceeding
may be arranged on a circle so that no two neighbouring numbers are coprime.