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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 April 20 08:47 EDT 2021. Contains 343125 sequences. (Running on oeis4.)