Polygon partitioned into triangles by multicoloured diagonals
Source: Kvant Magazine No. 3 2019 M2551
March 14, 2023
combinatoricsKvant
Problem Statement
The vertices of a convex polygon with sides are coloured with black and white. A diagonal is called multicoloured if its vertices have different colours. A colouring of the vertices is good if the polygon can be partitioned into triangles by using only multicoloured diagonals which do not intersect in the interior of the polygon. Find the number of good colourings. Proposed by S. Berlov