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 A250987 Number of (n+1) X (1+1) 0..2 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction. 1
 40, 158, 612, 2323, 8726, 32554, 120930, 447985, 1656600, 6118822, 22583412, 83309947, 307230262, 1132763986, 4175945922, 15393274457, 56738968328, 209129360814, 770792626564, 2840879847779, 10470404185174, 38589657774202 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 6*a(n-1) - 7*a(n-2) - 8*a(n-3) + 7*a(n-4) + 6*a(n-5) + a(n-6). Empirical g.f.: x*(40 - 82*x - 56*x^2 + 77*x^3 + 56*x^4 + 9*x^5) / ((1 - 2*x - x^2)*(1 - 4*x + 4*x^3 + x^4)). - Colin Barker, Nov 24 2018 EXAMPLE Some solutions for n=4: ..0..1....2..1....0..2....0..1....1..2....1..0....0..2....0..2....0..0....1..2 ..0..1....1..2....1..1....0..2....1..1....1..1....0..1....1..0....0..2....2..1 ..0..2....1..1....1..2....0..0....1..2....1..2....1..0....1..0....0..2....1..2 ..2..0....2..2....1..1....1..1....1..1....1..1....0..2....0..2....0..2....1..2 ..2..2....2..2....1..1....2..2....1..2....1..2....1..1....1..1....0..1....1..2 CROSSREFS Column 1 of A250994. Sequence in context: A135848 A089548 A282090 * A300963 A146762 A190073 Adjacent sequences: A250984 A250985 A250986 * A250988 A250989 A250990 KEYWORD nonn AUTHOR R. H. Hardin, Nov 29 2014 STATUS approved

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Last modified December 2 13:44 EST 2022. Contains 358510 sequences. (Running on oeis4.)