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A048467
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a(n) = T(6,n), array T given by A047858.
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1
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1, 8, 23, 55, 123, 267, 571, 1211, 2555, 5371, 11259, 23547, 49147, 102395, 212987, 442363, 917499, 1900539, 3932155, 8126459, 16777211, 34603003, 71303163, 146800635, 301989883, 620756987, 1275068411, 2617245691
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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.: (-9*x^2 + 3*x + 1)/((1-x)*(1-2*x)^2).
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MATHEMATICA
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LinearRecurrence[{5, -8, 4}, {1, 8, 23}, 30] (* or *) CoefficientList[ Series[ (-9x^2+3x+1)/((1-x)(1-2x)^2), {x, 0, 30}], x] (* Harvey P. Dale, Jul 07 2011 *)
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PROG
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(PARI) Vec((-9*x^2+3*x+1)/((1-x)*(1-2*x)^2) + O(x^40)) \\ Andrew Howroyd, Feb 15 2018
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CROSSREFS
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n-th difference of a(n), a(n-1), ..., a(0) is (7, 8, 9, ...).
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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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