A216722 Triangle read by rows: number of circular permutations of [1..n] with k modular progressions of rise 1, distance 1 and length 3 (n >= 3, 0 <= k <= n).
1, 0, 0, 1, 5, 0, 0, 0, 1, 18, 5, 0, 0, 0, 1, 95, 18, 6, 0, 0, 0, 1, 600, 84, 28, 7, 0, 0, 0, 1, 4307, 568, 116, 40, 8, 0, 0, 0, 1, 35168, 4122, 810, 156, 54, 9, 0, 0, 0, 1, 321609, 33910, 5975, 1100, 205, 70, 10, 0, 0, 0, 1
Offset: 3
Examples
Triangle begins: 1, 0, 0, 1; 5, 0, 0, 0, 1; 18, 5, 0, 0, 0, 1; 95, 18, 6, 0, 0, 0, 1; 600, 84, 28, 7, 0, 0, 0, 1; 4307, 568, 116, 40, 8, 0, 0, 0, 1; 35168, 4122, 810, 156, 54, 9, 0, 0, 0, 1; 321609, 33910, 5975, 1100, 205, 70, 10, 0, 0, 0, 1; ...
References
- Wayne M. Dymacek, Isaac Lambert and Kyle Parsons, Arithmetic Progressions in Permutations, http://math.ku.edu/~ilambert/CN.pdf, 2012.