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A187668
Number of (n+1)X(n+1) 0..1 arrays with each 2X2 subblock nonsingular and the array of 2X2 subblock determinants symmetric about the diagonal and antidiagonal
0
6, 24, 112, 974, 9928, 197152, 4547688, 200947508, 10553936856, 1051895421812, 125339066655024, 28078885802576900, 7575400864257725704
OFFSET
1,1
COMMENTS
Column 1 of A187670
EXAMPLE
Some solutions for 4X4
..1..0..1..0....0..1..1..1....0..1..0..1....1..1..1..0....1..1..1..1
..1..1..1..1....1..1..0..1....1..1..1..0....0..1..0..1....1..0..1..0
..1..0..1..0....1..0..1..1....0..1..0..1....1..0..1..0....0..1..0..1
..0..1..0..1....0..1..1..0....1..1..1..0....1..1..0..1....1..1..1..1
CROSSREFS
Sequence in context: A122739 A038380 A052745 * A273813 A293257 A223752
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 12 2011
STATUS
approved