1492804

Appears in sequences

• Irregular triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k isolated fixed points.at n=33A184178
• Number of permutations of {1,2,...,n} having no isolated fixed points. A fixed point j of a permutation is said to be isolated if neither j-1 nor j+1 is a fixed point. For example, 4135267 has only 3 as an isolated fixed point.at n=10A184179