collinear lattice points - All-Russian MO 2004 Regional (R4) 8.8
Source:
September 27, 2024
combinatoricscombinatorial geometrygeometrylattice points
Problem Statement
Is it possible to write natural numbers at all points of the plane with integer coordinates so that three points with integer coordinates lie on the same line if and only if the numbers written in them had a common divisor greater than one?