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 A227251 Number of n X n binary arrays indicating whether each 2X2 subblock of a larger binary array has lexicographically nondecreasing rows and columns, for some larger (n+1)X(n+1) binary array with rows and columns of the latter in lexicographically nondecreasing order 0
 1, 3, 36, 813, 44379, 6022992, 2110707595, 1972236759492 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Diagonal of A227256 LINKS EXAMPLE Some solutions for n=4 ..1..0..1..1....1..1..0..0....1..1..1..1....1..1..1..0....1..1..1..1 ..0..1..1..1....1..0..1..1....1..1..0..0....1..1..0..0....1..1..0..1 ..0..1..1..1....1..0..1..1....1..0..0..1....1..0..1..1....1..0..1..0 ..1..1..1..1....1..1..1..0....0..0..1..0....0..1..1..1....1..1..0..1 CROSSREFS Sequence in context: A122220 A186730 A224347 * A326273 A224006 A004824 Adjacent sequences:  A227248 A227249 A227250 * A227252 A227253 A227254 KEYWORD nonn AUTHOR R. H. Hardin Jul 04 2013 STATUS approved

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Last modified January 26 20:11 EST 2020. Contains 331288 sequences. (Running on oeis4.)