Turkish Project Euler Question 15 Lattice Paths

Turkish Project Euler Question 15 Lattice Paths

Turkish Project Euler Question 15 Lattice Paths

Starting from the top left of the following 2x2 grid and only moving right and down, you can reach the bottom right corner in exactly 6 different routes.

Turkish Project Euler Question 15 Lattice Paths

With these rules, how many different routes are there in a 20x20 grid?