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A213608
Number of n X n binary matrices with zero diagonal and x(i,j)+x(j,k)+x(k,i) not equal to one for i,j,k all different
0
1, 4, 25, 175, 1572, 19285, 321925, 7695406, 271013005
OFFSET
1,2
EXAMPLE
Some solutions for n=4
..0..1..1..1....0..0..0..1....0..1..1..1....0..1..1..0....0..1..1..1
..1..0..0..1....0..0..1..1....1..0..1..1....1..0..1..1....1..0..1..0
..1..0..0..1....1..0..0..1....1..1..0..0....0..1..0..1....1..0..0..0
..0..1..1..0....1..1..1..0....1..1..1..0....1..1..0..0....1..1..0..0
CROSSREFS
Sequence in context: A084210 A093683 A006348 * A369325 A324169 A213231
KEYWORD
nonn
AUTHOR
R. H. Hardin Jun 16 2012
STATUS
approved