Posted by **Mathslover** on Monday, May 27, 2013 at 4:21am.

How many permutations σ of the set {1,2,…,15} are there such that σ(1)=1,∣σ(n)−σ(n−1)∣≤2 for 2≤n≤15?

Details and assumptions

σ(n) denotes the nth position of the permutation.

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March 22, 2017
Posted by **Mathslover** on Monday, May 27, 2013 at 4:21am.

How many permutations σ of the set {1,2,…,15} are there such that σ(1)=1,∣σ(n)−σ(n−1)∣≤2 for 2≤n≤15?

Details and assumptions

σ(n) denotes the nth position of the permutation.

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