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A093390
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a(n) = floor(n/9) + floor((n+1)/9) + floor((n+2)/9).
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6
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0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 3, 3, 3, 3, 3, 3, 4, 5, 6, 6, 6, 6, 6, 6, 6, 7, 8, 9, 9, 9, 9, 9, 9, 9, 10, 11, 12, 12, 12, 12, 12, 12, 12, 13, 14, 15, 15, 15, 15, 15, 15, 15, 16, 17, 18, 18, 18, 18, 18, 18, 18, 19, 20, 21, 21, 21, 21, 21, 21, 21, 22, 23, 24, 24, 24, 24, 24, 24, 24, 25
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OFFSET
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0,9
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COMMENTS
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Half the domination number of the camel's graph (from Tamerlane Chess) on a 2 X (n-6) chessboard. - David Nacin, May 28 2017
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LINKS
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FORMULA
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G.f.: x^7 / ( (x^6+x^3+1)*(x-1)^2 ). - R. J. Mathar, Mar 22 2011
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MATHEMATICA
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Array[Total@ Map[Floor[#/9] &, # + Range[0, 2]] &, 80, 0] (* or *)
CoefficientList[Series[x^7/((x^6 + x^3 + 1) (x - 1)^2), {x, 0, 79}], x] (* Michael De Vlieger, Dec 12 2017 *)
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PROG
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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