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A216726
Triangle read by rows: number of circular permutations of [1..n] with k modular progressions of rise 1, distance 2 and length 3 (n >= 3, 0 <= k <= n).
1
11, 0, 0, 1, 6, 0, 0, 0, 0, 18, 5, 0, 0, 0, 1, 93, 18, 9, 0, 0, 0, 0, 600, 84, 28, 7, 0, 0, 0, 1, 4320, 512, 192, 0, 16, 0, 0, 0, 0, 35168, 4122, 810, 156, 54, 9, 0, 0, 0, 1, 321630, 34000, 5625, 1400, 200, 0, 25, 0, 0, 0, 0
OFFSET
3,1
REFERENCES
Wayne M. Dymacek, Isaac Lambert and Kyle Parsons, Arithmetic Progressions in Permutations, http://math.ku.edu/~ilambert/CN.pdf, 2012.
EXAMPLE
Triangle begins:
1 0 0 1
6 0 0 0 0
18 5 0 0 0 1
93 18 9 0 0 0 0
600 84 28 7 0 0 0 1
4320 512 192 0 16 0 0 0 0
35168 4122 810 156 54 9 0 0 0 1
321630 34000 5625 1400 200 0 25 0 0 0 0
...
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
N. J. A. Sloane, Sep 15 2012
STATUS
approved