

A279453


Triangle read by rows: T(n, k) is the number of nonequivalent ways to place k points on an n X n square grid so that no more than 2 points are on a vertical or horizontal straight line.


9



1, 1, 1, 1, 2, 1, 1, 1, 3, 8, 14, 17, 9, 2, 1, 3, 21, 73, 202, 306, 285, 115, 20, 1, 6, 49, 301, 1397, 4361, 9110, 11810, 8679, 2929, 288, 1, 6, 93, 890, 6582, 34059, 126396, 326190, 568134, 624875, 390426, 111798, 8791, 1, 10, 171, 2321, 24185, 185181, 1055025
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,5


COMMENTS

Length of nth row is A272651(n) + 1, where A272651(n) is the maximal number of points that can be placed under the condition mentioned.
Rotations and reflections of placements are not counted. If they are to be counted, see A279445.
For condition "no more than 2 points on a straight line at any angle", see A235453.


LINKS



EXAMPLE

The table begins with T(1, 0):
1 1
1 1 2 1 1
1 3 8 14 17 9 2
1 3 21 73 202 306 285 115 20
1 6 49 301 1397 4361 9110 11810 8679 2929 288
...
T(4, 3) = 73 because there are 73 nonequivalent ways to place 3 points on a 4 X 4 square grid so that no more than 2 points are on a vertical or horizontal straight line.


CROSSREFS



KEYWORD

nonn,tabf


AUTHOR



STATUS

approved



