A permutation σ:{1,2,…,n}→{1,2,…,n} is called straight if and only if for each integer k, 1≤k≤n−1 the following inequality is fulfilled
∣σ(k)−σ(k+1)∣≤2.
Find the smallest positive integer n for which there exist at least 2003 straight permutations.
Valentin Vornicu inequalitiessymmetrycombinatorics proposedcombinatorics