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A198909
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Number of nX3 0..7 arrays with values 0..7 introduced in row major order and no element equal to any horizontal or vertical neighbor
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2
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2, 34, 2051, 269940, 54381563, 13088156547, 3352514013159, 876632051686733, 230783525290600476, 60892298359864756053, 16078352442288906898825, 4246466444504000973551502, 1121629692628918068552449185
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 431*a(n-1) -53038*a(n-2) +2570412*a(n-3) -55789402*a(n-4) +610919758*a(n-5) -3707175288*a(n-6) +13010264300*a(n-7) -26380804149*a(n-8) +29517406483*a(n-9) -16243626186*a(n-10) +3246286680*a(n-11)
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EXAMPLE
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Some solutions with values 0 to 7 for n=4
..0..1..2....0..1..2....0..1..2....0..1..0....0..1..2....0..1..2....0..1..2
..3..4..0....3..4..5....3..0..4....2..3..4....1..3..4....3..0..4....3..4..0
..5..3..6....4..2..0....5..4..6....3..5..6....5..0..6....4..1..5....5..6..3
..0..1..7....1..6..7....6..1..7....7..4..0....0..1..7....6..7..4....3..5..7
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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