|
| |
|
|
A191691
|
|
Number of n X n symmetric binary matrices with each 1 adjacent to no more than 1 E, SE or S neighboring 1
|
|
1
|
|
|
|
2, 6, 32, 294, 4640, 125338, 5802288, 459958324, 62453890000, 14523496866976, 5784570667981520, 3945961499388113436, 4610186764537663968556, 9225021921428355206788506, 31615478219055162849230486428
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
|
|
|
EXAMPLE
|
Some solutions for n=5
..0..1..0..0..1....0..0..0..1..0....1..0..1..0..0....1..0..1..0..1
..1..1..0..0..1....0..1..0..0..1....0..0..0..1..0....0..0..1..0..1
..0..0..0..0..1....0..0..1..0..0....1..0..0..0..0....1..1..0..0..0
..0..0..0..0..0....1..0..0..0..0....0..1..0..0..1....0..0..0..1..0
..1..1..1..0..0....0..1..0..0..1....0..0..0..1..0....1..1..0..0..0
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
