MathDB
A regular hexagon with a side of $50$

Source: 2016 239 J3

October 11, 2020
combinatorics

Problem Statement

A regular hexagon with a side of 5050 was divided to equilateral triangles with unit side, parallel to the sides of the hexagon. It is allowed to delete any three nodes of the resulting lattice defining a segment of length 22. As a result of several such operations, exactly one node remains. How many ways is this possible?