A321532 a(n) gives the number of configurations of non-attacking rooks on an n X n chessboard such that the number of distinct directions between the rooks is given by A321531(n).

1, 2, 4, 8, 16, 168, 88, 592, 712

Offset

1,2

Links

Table of n, a(n) for n=1..9.

Example

For n = 5, the a(5) = 16 configurations of nonattacking rooks with the maximal number of directions between them are given by the following two chessboards under all eight symmetries of the square.
   +---+---+---+---+---+
  5| X |   |   |   |   |
   +---+---+---+---+---+
  4|   |   | X |   |   |
   +---+---+---+---+---+
  3|   |   |   | X |   |
   +---+---+---+---+---+
  2|   |   |   |   | X |
   +---+---+---+---+---+
  1|   | X |   |   |   |
   +---+---+---+---+---+
     A   B   C   D   E
   +---+---+---+---+---+
  5| X |   |   |   |   |
   +---+---+---+---+---+
  4|   |   |   | X |   |
   +---+---+---+---+---+
  3|   |   | X |   |   |
   +---+---+---+---+---+
  2|   |   |   |   | X |
   +---+---+---+---+---+
  1|   | X |   |   |   |
   +---+---+---+---+---+
     A   B   C   D   E

Crossrefs

Cf. A321531.

Sequence in context: A277280 A095197 A333302 * A061581 A046251 A281291

Adjacent sequences: A321529 A321530 A321531 * A321533 A321534 A321535

Keyword

nonn,more

Author

Peter Kagey, Nov 12 2018

Status

approved