A220905 Triangle read by rows: rook numbers of certain "probleme des rencontres" boards of the second kind of size n X k (0 <= k <= n).

1, 1, 0, 1, 2, 0, 1, 6, 6, 2, 1, 24, 132, 176, 24, 1, 60, 960, 4580, 5040, 552, 1, 120, 4260, 52960, 213000, 206592, 21280, 1, 210, 14070, 368830, 3762360, 13109712, 11404960, 1073160

Offset

0,5

Comments

Rows 0 through 2 were not given in the reference and should be checked. (There is a Maple program in the Appendix).

What are the row sums?

Links

Table of n, a(n) for n=0..35.

F. Alayont and N. Krzywonos, Rook Polynomials in Three and Higher Dimensions, 2012.

Example

Triangle begins:
  1
  1,   0
  1,   2,     0
  1,   6,     6,      2
  1,  24,   132,    176,      24
  1,  60,   960,   4580,    5040,      552
  1, 120,  4260,  52960,  213000,   206592,    21280
  1, 210, 14070, 368830, 3762360, 13109712, 11404960, 1073160
  ...

Crossrefs

Right-hand diagonal is A000186.

Sequence in context: A114329 A361956 A241011 * A353451 A226573 A260693

Adjacent sequences: A220902 A220903 A220904 * A220906 A220907 A220908

Keyword

nonn,tabl

Author

N. J. A. Sloane, Jan 02 2013

Status

approved