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A183248
Half the number of n X n binary arrays with the number of 1-1 adjacencies equal to the number of 0-0 adjacencies
1
1, 3, 25, 2101, 807261, 1333831052, 9146686484955, 257785338831598590, 29639472949422312375539, 13840053259049962085002931916, 26162867713485863870611094790664272
OFFSET
1,2
COMMENTS
Diagonal of A183253
LINKS
EXAMPLE
Some solutions with a(1,1)=0 for 4X4
..0..0..0..0....0..0..1..1....0..0..1..0....0..1..1..0....0..0..0..0
..1..0..1..1....0..1..0..1....0..1..1..0....0..0..1..1....1..0..0..0
..0..1..0..0....0..1..0..1....1..1..0..1....1..0..0..1....1..1..1..1
..1..1..1..1....0..0..1..1....0..0..1..0....1..0..1..0....1..1..0..1
CROSSREFS
Sequence in context: A309116 A094815 A246536 * A144788 A182135 A307654
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 03 2011
STATUS
approved