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Monotone lattice paths across a six-by-six board

Question

On a square lattice, a token starts at (0,0)(0,0) and must reach (6,6)(6,6). Every move takes it one unit right or one unit up. How many distinct routes are there?

Short answer

924924. Any route has 1212 moves, exactly 66 of them up. Choosing which 66 positions are the up-moves determines the route, giving (126)=924\binom{12}{6}=924.

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