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A201534
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Number of nX3 0..2 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor
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1
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3, 25, 111, 633, 3354, 16393, 72811, 293831, 1087857, 3735546, 12012530, 36466979, 105202136, 289996482, 767360174, 1956720113, 4824093641, 11531663892, 26793101230, 60636948110, 133921364986, 289121431541, 611037886807
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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) is a polynomial of degree 26 for n>13
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EXAMPLE
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Some solutions for n=7
..0..0..2....0..0..1....0..0..0....0..0..2....0..0..0....0..0..0....1..1..1
..0..2..2....0..2..1....0..0..0....0..1..2....0..2..2....0..0..2....1..1..2
..1..1..0....0..2..1....0..2..2....0..1..2....1..1..2....1..1..2....1..2..2
..2..1..0....2..0..0....1..1..1....0..1..2....1..1..2....1..2..1....1..2..2
..2..2..1....2..0..0....1..1..1....0..2..2....2..1..1....1..2..1....2..1..1
..2..2..1....2..0..2....2..0..0....2..2..1....2..1..1....2..2..1....2..2..1
..2..2..1....2..2..2....2..0..0....2..2..1....2..2..1....2..2..1....2..2..1
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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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