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A196538
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Number of nX2 0..4 arrays with each element equal to the number its horizontal and vertical neighbors less than or equal to itself
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1
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3, 23, 56, 461, 2897, 17967, 116911, 757146, 4893755, 31718101, 205477601, 1331145835, 8624488786, 55876739813, 362017883823, 2345474974395, 15196064614313, 98453588371088, 637869800997933, 4132686977034097
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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=4
..2..0....1..1....1..0....2..0....1..0....2..0....0..1....1..1....2..2....1..0
..2..1....3..3....3..3....0..3....2..3....0..2....2..3....2..3....0..1....2..3
..3..2....1..2....2..1....3..3....2..3....2..3....0..2....0..2....3..3....0..2
..0..1....0..1....2..0....0..1....2..0....1..0....1..2....1..2....1..1....1..2
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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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