A264667 Number of optimal solutions to the maximal number of diagonals problem studied in A264041.

2, 4, 28, 108, 2, 13968, 480, 7914054, 433284, 18726123500, 256, 178290006448984, 14454384, 6631290958957860856, 1401615406696, 941558205279187913101914, 1767136, 500995759754153499284692617816, 31163356068736, 984452644453618816989710782436259368

Offset: 1

Author

Rob Pratt, Nov 20 2015

Keywords

• nonn

Comments

Solutions that differ by a rotation and/or reflection are counted as different. - N. J. A. Sloane, Nov 20 2015

The paper by Boyland et al. gives a(13) = 14454384 and a(15) = 1401615406696. - Eric M. Schmidt, Aug 30 2017

Examples

			For n=2 the 4 solutions are:
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where the dot indicates an empty cell.
		

Links

• Peter Boyland, Gabriella Pintér, István Laukó, Ivan Roth, Jon E. Schoenfield, and Stephen Wasielewski, On the Maximum Number of Non-intersecting Diagonals in an Array, Journal of Integer Sequences, Vol. 20 (2017), Article 17.2.4.

Crossrefs

Cf. A264041.

Extensions

a(8)-a(13) from Andrew Howroyd, Feb 03 2018

a(14)-a(20) from Andrew Howroyd, Jun 22 2018