On The First Unknown Value of Two Functions For Convex Lattice \(v\)-Gons

Krzysztof Kolodziejczyk 1, Daria Olszewska1
1 Institute of Mathematics and Computer Science Wroclaw University of Technology Wybrzeze Wyspiariskiego 27, 50-370 Wroclaw, Poland

Abstract

Let \(a(v)\) and \(g(v)\) denote the least possible area and the least possible number of lattice points in the interior of a convex lattice \(v\)-gon, respectively. Many lower and upper bounds for \(a(v)\) and \(g(v)\) are known for every \(v\). However, the exact values of these two functions are only known for \(v \leq 10\) and \(v \in \{12, 13, 14, 16, 18, 20, 22\}\). The purpose of this paper is to answer the following Open Question 1 from \([13]\): What is the exact value of \(a(11)\)? We answer this question by proving that \(a(11) = 21.5\). On our way to achieve this goal, we also prove that \(g(11) = 17\).