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A190604
Number of (n+2)X(n+2) symmetric binary matrices without the pattern 1 0 1 diagonally
1
56, 672, 14112, 522144, 33939360, 3869087040, 773817408000, 271609910208000, 167311704688128000, 180863952767866368000, 343098918400642500096000, 1142176299355738882819584000, 6672593940836226553432009728000
OFFSET
1,1
LINKS
EXAMPLE
Some solutions for 4X4
..1..1..1..0....0..0..1..0....1..0..1..0....0..1..1..0....1..1..1..1
..1..0..1..1....0..0..0..1....0..1..1..1....1..0..1..0....1..0..1..0
..1..1..0..1....1..0..1..1....1..1..1..0....1..1..1..0....1..1..0..1
..0..1..1..0....0..1..1..0....0..1..0..0....0..0..0..0....1..0..1..1
CROSSREFS
Sequence in context: A027813 A199914 A190535 * A136006 A138410 A240269
KEYWORD
nonn
AUTHOR
R. H. Hardin May 13 2011
STATUS
approved