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A067089
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Floor(X/Y) where X = concatenation of (2n), (2n-1), ... down to n+1 and Y = concatenation of n, n-1, n-2, ... down to 1.
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9
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2, 2, 2, 2, 2, 185, 18461, 1842626, 183987603, 1837682236, 1999303871, 2000827643, 2000777468, 2000722020, 2000673854, 2000631711, 2000594530, 2000561482, 2000531914, 2000505305, 2000481231, 2000459347, 2000439367
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listen;
history;
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OFFSET
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1,1
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LINKS
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EXAMPLE
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a(6) = floor(121110987/654321) = floor(185.094146451053840546153951959359) = 185.
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MATHEMATICA
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f[n_] := (k = 1; x = y = "0"; While[k < n + 1, x = StringJoin[x, ToString[2n - k + 1]]; y = StringJoin[ToString[2k - 1], y]; k++ ]; Return[ Floor[10* ToExpression[x] / ToExpression[y]]] ); Table[ f[n], {n, 1, 25} ]
fd[st_, en_]:=FromDigits[Flatten[IntegerDigits/@Range[st, en, -1]]]; Table[ Floor[fd[2n, n+1]/fd[n, 1]], {n, 30}] (* Harvey P. Dale, Jul 04 2013 *)
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CROSSREFS
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KEYWORD
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easy,base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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