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A217882
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Number of n element 0..2 arrays with each element the minimum of 7 adjacent elements of a random 0..2 array of n+6 elements.
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1
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3, 9, 22, 46, 86, 148, 239, 367, 546, 806, 1212, 1896, 3107, 5285, 9166, 15926, 27386, 46326, 77008, 126100, 204345, 329557, 531883, 862787, 1409973, 2321625, 3845207, 6389207, 10621657, 17628795, 29173804, 48123884, 79161386, 129972892
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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) + 3*a(n-8) - a(n-9) + a(n-10) + a(n-11) + a(n-12) + a(n-13) + a(n-14) + a(n-15).
Empirical g.f.: x*(1 + x^2 + x^3 + x^4 + x^5 + x^6 + x^7)*(3 + x^2 + x^3 + x^4 + x^5 + x^6 + x^7) / ((1 - x + x^4 + x^5 + x^6 + x^7)*(1 - 2*x + x^2 - x^4 - x^8)). - Colin Barker, Jul 23 2018
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EXAMPLE
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Some solutions for n=4:
..0....0....0....0....0....0....0....0....0....2....0....2....0....1....0....0
..0....2....0....1....0....1....0....0....1....2....2....2....0....2....1....0
..1....1....2....2....2....2....1....1....1....2....2....2....0....2....1....2
..2....1....2....0....0....2....0....1....0....2....0....0....0....2....2....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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