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A153171
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First differences of A046163.
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1
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6, 6, -6, 24, 12, -24, 54, 18, -54, 96, 24, -96, 150, 30, -150, 216, 36, -216, 294, 42, -294, 384, 48, -384, 486, 54, -486, 600, 60, -600, 726, 66, -726, 864, 72, -864, 1014, 78, -1014, 1176, 84, -1176, 1350, 90, -1350, 1536, 96, -1536, 1734, 102, -1734
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OFFSET
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0,1
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LINKS
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FORMULA
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G.f.: 6*(x^4+2*x^3+x^2+2*x+1) / ((x-1)^2*(x^2+x+1)^3). - Colin Barker, Nov 04 2014
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MATHEMATICA
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Differences[Table[Denominator[(n-1)^2/(n^2+n+1)], {n, 1, 50}]] (* Vaclav Kotesovec, Nov 04 2014 *)
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PROG
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(PARI) Vec(6*(x^4+2*x^3+x^2+2*x+1)/((x-1)^2*(x^2+x+1)^3) + O(x^100)) \\ Colin Barker, Nov 04 2014
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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