lattice point visible from the origin
Source: 11-th Taiwanese Mathematical Olympiad 2002
January 23, 2007
geometrycombinatorics unsolvedcombinatorics
Problem Statement
A lattice point in the plane is said to be visible from the origin if the line segment does not contain any other lattice points. Show that for any positive integer , there is square of area such that none of the lattice points inside the square is visible from the origin.