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 A032260 Number of n X n (0,1) matrices such that each row and each column is nondecreasing or nonincreasing. 5
 2, 16, 102, 528, 2470, 11016, 47950, 205792, 874998, 3694920, 15519262, 64899456, 270415262, 1123264408, 4653525150, 19234571968, 79342610902, 326704870152, 1343120023678, 5513861152000, 22606830725598, 92580354402712, 378737813468542, 1547884976787648 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Eric M. Schmidt, Table of n, a(n) for n = 1..1000 Don Coppersmith, Ponder This: IBM Research Monthly Puzzles, March challenge FORMULA a(n) = 2*n*(binomial(2*n, n)-n). G.f.: 4*x/(1-4*x)^(3/2)-2*x*(1+x)/(1-x)^3. - Vladimir Baltic and Vladeta Jovovic, Jul 10 2003 CROSSREFS The number of n X n 0, 1 matrices such that each row and each column is increasing is in sequence A000984. Cf. A000984, A062528, A045992, A016742, A086113 - A086115. Sequence in context: A319603 A043016 A197202 * A197800 A209645 A207062 Adjacent sequences:  A032257 A032258 A032259 * A032261 A032262 A032263 KEYWORD nonn AUTHOR Yuval Dekel (dekelyuval(AT)hotmail.com), Jun 25 2003 EXTENSIONS Extended by Vladimir Baltic and Vladeta Jovovic, Jul 10 2003 More terms from Eric M. Schmidt, May 01 2013 STATUS approved

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Last modified January 18 20:57 EST 2019. Contains 319282 sequences. (Running on oeis4.)