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A250882 Number of (5+1) X (n+1) 0..3 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
37130, 131068, 317878, 629528, 1097986, 1755220, 2633198, 3763888, 5179258, 6911276, 8991910, 11453128, 14326898, 17645188, 21439966, 25743200, 30586858, 36002908, 42023318, 48680056, 56005090, 64030388, 72787918, 82309648, 92627546 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..156

FORMULA

Empirical: a(n) = 5328*n^3 + 14468*n^2 + 13238*n + 4096.

Conjectures from Colin Barker, Nov 22 2018: (Start)

G.f.: 2*x*(18565 - 8726*x + 8193*x^2 - 2048*x^3) / (1 - x)^4.

a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>4.

(End)

EXAMPLE

Some solutions for n=2:

..1..1..1....2..2..2....1..1..1....2..2..2....0..0..1....2..3..3....0..0..0

..2..2..2....0..0..0....1..1..1....3..3..3....1..1..2....1..2..3....2..3..3

..1..1..1....3..3..3....2..2..2....1..1..2....2..2..3....1..2..3....0..1..1

..3..3..3....2..2..2....2..2..2....0..0..2....0..1..2....1..2..3....2..3..3

..2..2..2....0..1..1....3..3..3....1..1..3....1..2..3....0..2..3....1..3..3

..0..1..2....0..2..3....2..3..3....0..0..2....0..1..2....0..2..3....1..3..3

CROSSREFS

Row 5 of A250877.

Sequence in context: A206051 A279862 A112728 * A219363 A254564 A151630

Adjacent sequences:  A250879 A250880 A250881 * A250883 A250884 A250885

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 28 2014

STATUS

approved

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Last modified August 14 08:08 EDT 2020. Contains 336478 sequences. (Running on oeis4.)