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MathNet 2017-part-07 — 172 problems (EN–VI) Question 53

Math Olympiad Vault · MathNet 2017-part-07 — 172 problems (EN–VI)

Question 53

Yang has the sequence of integers $1,2, \ldots, 2017$. He makes 2016 swaps in order, where a swap changes the positions of two integers in the sequence. His goal is to end with $2,3, \ldots, 2017,1$. How many different sequences of swaps can Yang do to achieve his goal?