Constraint Satisfaction Programming for the No-three-in-line Problem

Abstract

Using a constraint satisfaction approach, we exhibit configurations of $2n$ points on the $n\times n$ grid for all $n\le 60$ with no three collinear. Consequently, the smallest $n$ for which it is unknown whether $D(n)=2n$ increases from $47$ to $61$.

16 pages, 6 figures, supplementary material on https://github.com/ThomasPrellberg/no-three-in-line---CP-SAT