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A255104
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Number of length n+5 0..2 arrays with at most one downstep in every 5 consecutive neighbor pairs.
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1
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294, 597, 1302, 2951, 6582, 14001, 29147, 61542, 133392, 292534, 634197, 1353282, 2874273, 6149472, 13283988, 28746325, 61881375, 132509427, 283590718, 609038592, 1311917331, 2825639015, 6072583563, 13028913003, 27962048781
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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) -3*a(n-2) +a(n-3) +18*a(n-5) -29*a(n-6) +12*a(n-7) -6*a(n-10) +3*a(n-11).
Empirical g.f.: x*(294 - 285*x + 393*x^2 + 542*x^3 + 1038*x^4 - 3486*x^5 + 1719*x^6 - 129*x^7 - 318*x^8 - 684*x^9 + 441*x^10) / (1 - 3*x + 3*x^2 - x^3 - 18*x^5 + 29*x^6 - 12*x^7 + 6*x^10 - 3*x^11). - Colin Barker, Jan 24 2018
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EXAMPLE
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Some solutions for n=4:
..2....0....0....2....1....1....1....0....0....0....2....1....1....0....2....0
..0....0....1....0....2....1....1....0....0....0....2....1....1....1....0....2
..1....0....1....0....0....0....1....1....1....2....1....2....0....1....0....2
..1....0....2....0....1....0....2....0....1....2....1....0....1....2....1....2
..1....1....0....1....1....1....1....1....1....2....1....1....1....2....1....2
..1....1....2....1....1....1....1....1....1....2....1....2....2....2....1....0
..0....0....2....1....1....2....1....1....1....1....1....2....2....0....0....1
..0....0....2....1....0....1....2....2....1....1....2....2....0....1....0....1
..2....2....2....0....0....1....2....2....1....1....2....0....0....1....0....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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