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A234267
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Expansion of (1-x)/((1-2*x)*(1-5*x+6*x^2-x^3)).
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1
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1, 6, 26, 99, 353, 1213, 4078, 13529, 44518, 145750, 475683, 1549457, 5040985, 16387962, 53251549, 172987342, 561848146, 1824633763, 5925198353, 19240299477, 62475465318, 202861776657, 658698488006, 2138801439710, 6944686435779, 22549338805857, 73217410408753, 237735772753266, 771923874337397
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OFFSET
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0,2
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LINKS
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FORMULA
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G.f.: (1-x)/((1-2*x)*(1-5*x+6*x^2-x^3)).
a(n) = 7*a(n-1)-16*a(n-2)+13*a(n-3)-2*a(n-4) for n>3, a(0)=1, a(1)=6, a(2)=26, a(3)=99. - Philippe Deléham, Dec 25 2013
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MATHEMATICA
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CoefficientList[Series[(1 - x)/((1 - 2 x) (1 - 5 x + 6 x^2 - x^3)), {x, 0, 40}], x] (* Vincenzo Librandi, Apr 28 2014 *)
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PROG
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(Magma) I:=[1, 6, 26, 99]; [n le 4 select I[n] else 7*Self(n-1)-16*Self(n-2)+13*Self(n-3)-2*Self(n-4): n in [1..30]]; // Vincenzo Librandi, Apr 28 2014
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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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