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A221287
Equals two maps: number of n X n binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..3 n X n array
0
1, 4, 92, 9107, 4983598, 10344276279
OFFSET
1,2
COMMENTS
Diagonal of A221290
EXAMPLE
Some solutions for n=3
..0..0..0....0..0..1....0..1..0....0..0..0....0..0..1....0..1..1....0..0..1
..1..1..0....1..0..1....0..1..0....1..0..1....0..1..0....0..1..1....1..0..1
..1..1..0....1..1..0....1..1..0....1..0..0....1..1..0....0..1..0....1..0..0
CROSSREFS
Sequence in context: A012071 A012217 A012135 * A177411 A219891 A050878
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 09 2013
STATUS
approved