|
|
A215873
|
|
Number of permutations of 0..floor((5*n-2)/2) on odd squares of an 5Xn array such that each row, column, diagonal and (downwards) antidiagonal of odd squares is increasing
|
|
0
|
|
|
1, 1, 1, 4, 20, 189, 1642, 26451, 307874, 7027942, 98057806, 2850280812, 44974137856
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,4
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
Some solutions for n=5
..x..0..x..2..x....x..0..x..1..x....x..0..x..1..x....x..0..x..2..x
..1..x..3..x..5....2..x..3..x..5....2..x..3..x..5....1..x..3..x..5
..x..4..x..7..x....x..4..x..7..x....x..4..x..6..x....x..4..x..6..x
..6..x..8..x..9....6..x..8..x.10....7..x..8..x.10....7..x..8..x..9
..x.10..x.11..x....x..9..x.11..x....x..9..x.11..x....x.10..x.11..x
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|