Lattice paths
Starting in the top left corner of a \( 2×2 \) grid, and only being able to move to the right and down, there are exactly \( 6 \) routes to the bottom right corner.
How many such routes are there through a \( 20×20 \) grid?
Starting in the top left corner of a \( 2×2 \) grid, and only being able to move to the right and down, there are exactly \( 6 \) routes to the bottom right corner.
How many such routes are there through a \( 20×20 \) grid?
