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A233840
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Number of (n+2) X (3+2) 0..3 arrays with no increasing sequence of length 3 horizontally or antidiagonally downwards.
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1
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480071296, 326595297792, 220722832237568, 149185819914631168, 100827647839987847168, 68144762665642379485184, 46055875906826738439045120, 31127025414950384068108124160
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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) = 676*a(n-1) +6980*a(n-2) -4863328*a(n-3) +41995792*a(n-4) +7953854528*a(n-5) -184904579136*a(n-6) +809889143808*a(n-7) +10973630976000*a(n-8) -119806280073216*a(n-9) +355504517218304*a(n-10) +141549729742848*a(n-11) -1945470193631232*a(n-12) +423049732030464*a(n-13) +1344200025047040*a(n-14) -382139212234752*a(n-15) +171684875206656*a(n-16).
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EXAMPLE
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Some solutions for n=1
..0..0..0..1..0....0..0..0..1..0....0..0..0..1..0....0..0..0..0..0
..0..2..1..2..2....1..0..0..2..1....1..2..0..1..0....1..2..0..1..1
..0..2..1..2..0....2..2..2..3..0....1..2..1..0..3....2..1..0..1..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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