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A222837
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Number of nX7 0..3 arrays with no element equal to another at a city block distance of exactly two, and new values 0..3 introduced in row major order
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1
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163, 6144, 5832, 10584, 22848, 55296, 138240, 301056, 642048, 1382400, 3022848, 6690816, 14816256, 32741376, 72244224, 159258624, 351111168, 774297600, 1707764736, 3766818816, 8308300800, 18324658176, 40416165888, 89140107264
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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) = 2*a(n-1) +a(n-3) -2*a(n-4) +4*a(n-5) +a(n-6) -a(n-9) for n>14
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EXAMPLE
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Some solutions for n=4
..0..1..2..2..3..1..2....0..1..1..2..0..0..1....0..1..1..2..3..1..2
..2..3..0..0..3..1..0....3..3..0..2..3..3..1....0..3..3..2..0..0..2
..2..3..1..1..2..2..3....1..2..0..1..1..2..0....1..2..0..1..1..3..3
..1..0..2..3..0..0..3....1..2..3..3..0..2..3....3..2..0..3..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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