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 A250761 Number of (6+1) X (n+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction. 1
 9585, 22197, 40023, 63063, 91317, 124785, 163467, 207363, 256473, 310797, 370335, 435087, 505053, 580233, 660627, 746235, 837057, 933093, 1034343, 1140807, 1252485, 1369377, 1491483, 1618803, 1751337, 1889085, 2032047, 2180223, 2333613 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..209 FORMULA Empirical: a(n) = 2607*n^2 + 4791*n + 2187. Conjectures from Colin Barker, Nov 18 2018: (Start) G.f.: 3*x*(3195 - 2186*x + 729*x^2) / (1 - x)^3. a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>3. (End) EXAMPLE Some solutions for n=4: ..2..2..2..2..2....0..0..0..0..0....2..2..2..2..2....2..2..2..2..2 ..0..0..0..0..0....1..1..1..1..1....1..1..1..1..1....0..0..0..0..0 ..2..2..2..2..2....1..1..1..2..2....0..0..0..0..0....2..2..2..2..2 ..2..2..2..2..2....0..0..0..1..1....1..1..1..1..1....2..2..2..2..2 ..2..2..2..2..2....0..0..0..1..1....2..2..2..2..2....2..2..2..2..2 ..1..2..2..2..2....1..1..1..2..2....0..1..1..1..1....1..1..1..1..1 ..0..1..1..2..2....1..1..1..2..2....0..2..2..2..2....0..0..0..0..2 CROSSREFS Row 6 of A250755. Sequence in context: A133449 A275687 A210409 * A038825 A038814 A230020 Adjacent sequences:  A250758 A250759 A250760 * A250762 A250763 A250764 KEYWORD nonn AUTHOR R. H. Hardin, Nov 27 2014 STATUS approved

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Last modified March 30 12:10 EDT 2020. Contains 333125 sequences. (Running on oeis4.)