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A198899
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Number of n X n 0..4 arrays with values 0..4 introduced in row major order and no element equal to any horizontal or vertical neighbor
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2
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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Some solutions with values 0 to 4 for n=4
..0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
..1..2..1..0....1..2..1..2....1..2..1..2....1..0..2..0....1..0..1..0
..0..1..3..4....2..3..0..1....3..0..2..0....3..4..0..3....2..1..0..3
..3..2..0..3....4..1..2..4....4..3..1..3....2..1..2..4....1..4..1..2
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MATHEMATICA
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A198906 = Cases[Import["https://oeis.org/A198906/b198906.txt", "Table"], {_, _}][[All, 2]];
a[n_] := A198906[[2 n^2 - 2 n + 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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