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A190340 Number of (n+1)X(n+1) symmetric binary matrices without the pattern 1 1 antidiagonally 1
4, 12, 72, 720, 10800, 259200, 10368000, 673920000, 70087680000, 11774730240000, 3214501355520000, 1420809599139840000, 1014458053785845760000, 1171699052122651852800000, 2191077227469358964736000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..47

EXAMPLE

Some solutions for 3X3

..1..0..1....0..0..1....0..0..1....0..0..0....1..0..0....1..0..1....0..0..0

..0..0..0....0..0..0....0..0..0....0..1..0....0..1..0....0..0..0....0..0..0

..1..0..0....1..0..1....1..0..0....0..0..1....0..0..0....1..0..1....0..0..0

CROSSREFS

Sequence in context: A323295 A166746 A052558 * A232325 A291487 A133666

Adjacent sequences:  A190337 A190338 A190339 * A190341 A190342 A190343

KEYWORD

nonn

AUTHOR

R. H. Hardin May 09 2011

STATUS

approved

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Last modified August 24 16:10 EDT 2019. Contains 326295 sequences. (Running on oeis4.)