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A318778
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Number of different positions that an elementary sphinx can occupy in a sphinx of order n.
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1
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OFFSET
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1,2
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LINKS
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FORMULA
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G.f.: x*(1 + 25*x + 47*x^2 - x^3) / (1 - x)^3.
a(n) = 44 - 80*n + 36*n^2 for n>1.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>4.
(End)
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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