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A202910
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Number of nX2 0..7 arrays with every nonzero element less than or equal to some horizontal or vertical neighbor
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1
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8, 680, 31984, 1194376, 44344428, 1707628408, 66085464308, 2542636404496, 97688506009926, 3756426746800752, 144493565678435826, 5557405757222316520, 213730533301348703138, 8219904362839412920344, 316134938792029283711026
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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) = 36*a(n-1) -238*a(n-2) +11172*a(n-3) +34719*a(n-4) +951582*a(n-5) +3347114*a(n-6) +29399988*a(n-7) +80056473*a(n-8) +374118253*a(n-9) +709288548*a(n-10) +1969872705*a(n-11) +2317452024*a(n-12) +3743198992*a(n-13) +2076708096*a(n-14) +1625702400*a(n-15)
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EXAMPLE
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Some solutions for n=4
..7..6....3..3....4..2....4..5....2..6....7..5....3..0....2..3....2..0....1..5
..7..5....1..3....4..1....0..6....1..6....7..4....3..0....7..3....3..1....7..5
..5..6....5..4....3..1....4..6....7..6....1..4....2..2....7..2....3..2....7..1
..1..6....5..0....4..4....4..6....7..0....1..0....3..3....3..2....0..0....2..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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