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A084858
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Binomial transform of A001651.
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11
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1, 3, 9, 24, 60, 144, 336, 768, 1728, 3840, 8448, 18432, 39936, 86016, 184320, 393216, 835584, 1769472, 3735552, 7864320, 16515072, 34603008, 72351744, 150994944, 314572800, 654311424, 1358954496, 2818572288, 5838471168, 12079595520
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OFFSET
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0,2
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COMMENTS
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LINKS
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FORMULA
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G.f.: (x^2 - x + 1)/(1-2*x)^2.
a(n) = 3*(0^n/3 + 2^n + n*2^n)/4.
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MATHEMATICA
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CoefficientList[Series[(x^2-x+1)/(1-2x)^2, {x, 0, 40}], x] (* Vincenzo Librandi, Jun 24 2012 *)
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PROG
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(Magma) I:=[1, 3, 9]; [n le 3 select I[n] else 4*Self(n-1)-4*Self(n-2): n in [1..50]]; // Vincenzo Librandi, Jun 24 2012
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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