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A190050
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Expansion of ((1-x)*(3*x^2-3*x+1))/(1-2*x)^3
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3
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1, 2, 6, 17, 46, 120, 304, 752, 1824, 4352, 10240, 23808, 54784, 124928, 282624, 634880, 1417216, 3145728, 6946816, 15269888, 33423360, 72876032, 158334976, 342884352, 740294656, 1593835520, 3422552064
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OFFSET
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0,2
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COMMENTS
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The second left hand column of triangle A175136.
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LINKS
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FORMULA
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G.f.: ((1-x)*(3*x^2-3*x+1))/(1-2*x)^3.
a(n) = (n^2 + 5*n + 10)*2^(n-4) for n >=1 with a(0)=1.
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MAPLE
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MATHEMATICA
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Join[{1}, LinearRecurrence[{6, -12, 8}, {2, 6, 17}, 30]] (* or *) CoefficientList[Series[((1-x)*(3*x^2-3*x+1))/(1-2*x)^3, {x, 0, 50}], x] (* G. C. Greubel, Jan 10 2018 *)
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PROG
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(PARI) x='x+O('x^30); Vec(((1-x)*(3*x^2-3*x+1))/(1-2*x)^3) \\ G. C. Greubel, Jan 10 2018
(PARI) for(n=0, 30, print1(if(n==0, 1, (n^2 + 5*n + 10)*2^(n-4)), ", ")) \\ G. C. Greubel, Jan 10 2018
(Magma) [1] cat [(n^2 + 5*n + 10)*2^(n-4): n in [1..30]]; // G. C. Greubel, Jan 10 2018
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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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