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A227098
Number of n X n 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(n+1) binary array having a sum of two, with rows and columns of the latter in lexicographically nondecreasing order
0
2, 15, 239, 8427, 754758, 180409504
OFFSET
1,1
COMMENTS
Diagonal of A227103
EXAMPLE
Some solutions for n=4
..0..0..1..1....0..1..0..0....0..0..0..0....0..1..1..0....0..0..1..0
..0..1..0..0....1..0..1..0....0..0..0..1....1..1..0..1....0..0..0..0
..1..1..1..0....1..0..0..1....1..0..1..0....1..1..0..0....1..0..0..1
..1..1..0..0....1..0..0..1....1..0..0..0....0..0..1..1....1..1..0..1
CROSSREFS
Sequence in context: A302358 A192561 A356587 * A180610 A156750 A292798
KEYWORD
nonn
AUTHOR
R. H. Hardin Jul 01 2013
STATUS
approved