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A196424
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Number of nX2 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than itself
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2
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3, 23, 123, 809, 5274, 33923, 219807, 1424725, 9226721, 59782080, 387322045, 2509377827, 16258011561, 105333834791, 682445646554, 4421489543317, 28646335313891, 185596395723437, 1202458284920023, 7790592650792034
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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) = 3*a(n-1) +22*a(n-2) +24*a(n-3) -86*a(n-4) -296*a(n-5) -126*a(n-6) +428*a(n-7) +420*a(n-8) +239*a(n-9) +92*a(n-10) -147*a(n-11) +22*a(n-12) +26*a(n-13) -13*a(n-14) +5*a(n-15)
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EXAMPLE
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Some solutions for n=3
..2..0....0..0....0..0....0..0....2..0....2..0....1..2....0..2....2..0....1..0
..0..0....2..3....3..2....0..0....1..1....1..3....0..0....3..0....1..3....2..2
..0..0....0..1....0..1....1..2....0..2....0..1....2..1....1..0....0..0....0..0
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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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