A permutation with a special property question

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SUMMARY

The discussion revolves around a mathematical problem involving permutations of the set {1, 2, ..., 2n}. Specifically, it addresses the condition that the absolute differences between consecutive elements in the permutation must be unique. The conclusion drawn is that if the even-indexed elements satisfy the condition 1 ≤ a_{2i} ≤ n for i = 1, 2, ..., n, then it must hold that a_{1} = a_{2n} + n. The participants express difficulty in proving this assertion, indicating a need for deeper exploration of the properties of permutations.

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Hells_Kitchen
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Hi there,
i was wondering if you had any thoughts on the following question:

Let (a_{1}, a_{2}, ..., a_{2n}) be a permutation of {1, 2, ..., 2n} so that |a_{i} - a_{i+1}| \neq |a_{j} - a_{j+1}|, whenever i \neq j.

Show that a_{1} = a_{2n} + n, if 1 \leq a_{2i} \leq n for i = 1,2, ..., n
 
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still no ideas??
 
According to my calculations (proof) it's not possible.. Try proving this..
 
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