521606

Appears in sequences

• Number of permutations of {1,2,...,n} where adjacent elements differ in value by 3 or more.at n=11A127697
• Number of permutations of 1..2*n+7 with no adjacent elements within n in value.at n=2A179965
• Triangle T(n,k) giving the number of permutations of 1..n with no adjacent elements within k in value, for n >= 2, 1 <= k <= floor(n/2).at n=27A322255