A264667 - OEIS

%I #27 Jun 23 2018 02:36:17

%S 2,4,28,108,2,13968,480,7914054,433284,18726123500,256,

%T 178290006448984,14454384,6631290958957860856,1401615406696,

%U 941558205279187913101914,1767136,500995759754153499284692617816,31163356068736,984452644453618816989710782436259368

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

%C Solutions that differ by a rotation and/or reflection are counted as different. - _N. J. A. Sloane_, Nov 20 2015

%C The paper by Boyland et al. gives a(13) = 14454384 and a(15) = 1401615406696. - _Eric M. Schmidt_, Aug 30 2017

%H Peter Boyland, Gabriella Pintér, István Laukó, Ivan Roth, Jon E. Schoenfield, and Stephen Wasielewski, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL20/Pinter/pinter3.html">On the Maximum Number of Non-intersecting Diagonals in an Array</a>, Journal of Integer Sequences, Vol. 20 (2017), Article 17.2.4.

%e For n=2 the 4 solutions are:

%e .\

%e \\

%e --

%e /.

%e //

%e --

%e \\

%e \.

%e --

%e //

%e ./

%e --

%e where the dot indicates an empty cell.

%Y Cf. A264041.

%K nonn

%O 1,1

%A _Rob Pratt_, Nov 20 2015

%E a(8)-a(13) from _Andrew Howroyd_, Feb 03 2018

%E a(14)-a(20) from _Andrew Howroyd_, Jun 22 2018