|
|
A193221
|
|
Number of n X n symmetric 0..3 arrays with no element equal to the sum mod 4 of any two of its horizontal and vertical neighbors
|
|
0
|
|
|
4, 27, 201, 2791, 77245, 4482957, 547681823, 138848752487, 71804214564925, 74948295541392333, 157072100264370812423, 659458569446754937883175, 5541778577891773501263989795, 93184605443427688066128310380963
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
EXAMPLE
|
Some solutions for 4X4
..1..1..3..3....1..1..1..3....3..3..1..3....1..3..3..3....3..3..1..3
..1..3..1..1....1..3..1..3....3..3..3..1....3..3..1..3....3..1..3..1
..3..1..1..1....1..1..1..1....1..3..3..1....3..1..3..1....1..3..1..3
..3..1..1..1....3..3..1..3....3..1..1..3....3..3..1..1....3..1..3..3
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|