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A154627
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Expansion of (1-5x)/(1-8x+4x^2).
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1
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1, 3, 20, 148, 1104, 8240, 61504, 459072, 3426560, 25576192, 190903296, 1424921600, 10635759616, 79386390528, 592548085760, 4422839123968, 33012520648704, 246408808693760, 1839220386955264, 13728127860867072
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OFFSET
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0,2
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COMMENTS
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Hankel transform of 1,1,4,18,88,.... (see A081671).
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LINKS
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FORMULA
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a(n) = 8*a(n-1) - 4*a(n-2), n > 1; a(0)=1, a(1)=3. [Philippe Deléham, Feb 02 2009]
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MAPLE
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A[0]:= 1: A[1]:= 3:
for n from 2 to 100 do A[n]:= 8*A[n-1]-4*A[n-2] od:
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MATHEMATICA
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LinearRecurrence[{8, -4}, {1, 3}, 20] (* Harvey P. Dale, Aug 10 2014 *)
CoefficientList[Series[(1 - 5 x)/(1 - 8 x + 4 x^2), {x, 0, 50}], x] (* Vincenzo Librandi, Aug 10 2014 *)
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PROG
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(PARI) Vec((1-5*x)/(1-8*x+4*x^2)+O(x^50)) \\ Michel Marcus, Aug 10 2014
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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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