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A278722
Number of nX3 0..3 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order.
1
20, 275, 3232, 33466, 306070, 2487889, 18151220, 120104810, 727684612, 4070893254, 21181152380, 103146867706, 472709673984, 2048611972127, 8431440391174, 33079800818118, 124138709933301, 446936241587393
OFFSET
1,1
COMMENTS
Column 3 of A278727.
FORMULA
Empirical polynomial of degree 45 (see link above)
EXAMPLE
Some solutions for n=4
..0..0..0. .2..0..0. .1..0..0. .1..0..0. .2..1..0. .1..0..0. .1..1..0
..1..1..0. .2..1..1. .2..0..0. .1..3..2. .2..1..0. .1..1..0. .2..1..0
..2..2..2. .2..2..2. .3..2..1. .3..1..3. .2..1..2. .2..2..3. .2..3..3
..3..0..2. .2..2..2. .3..3..1. .3..3..2. .2..3..3. .3..3..0. .3..1..0
CROSSREFS
Cf. A278727.
Sequence in context: A019613 A021514 A121117 * A021264 A025928 A004334
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 27 2016
STATUS
approved