MathCastle
ChallengeMedium

Challenge · Medium problem

Among all lattice paths from (0,0)(0,0) to (12,0)(12,0) using steps (1,1)(1,1) and (1,−1)(1,-1) that never go below the xx-axis, how many have exactly 33 peaks, where a peak is an up-step immediately followed by a down-step?

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