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A123394
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Values X satisfying the equation 7(X-Y)^4-8XY=0, where X>=Y.
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1
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0, 64, 54000, 48387776, 43449047520, 39017102749504, 35037312017058000, 31463467090220398016, 28254158407188855215040, 25372202786113074403284544, 22784209847768873321556750000
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OFFSET
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0,2
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COMMENTS
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To find Y values: b(n) = c(n)*(-1+d(n)) which gives: 0, 56, 53760, 48380584, 43448832000,...
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LINKS
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FORMULA
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a(n) = c(n)*(1+d(n)) with c(0) = 0, c(1) = 4 and c(n) = 30*c(n-1) - c(n-2), d(0) = 1, d(1) = 15 and d(n) = 30*d(n-1) - d(n-2).
For n>=4, a(n) = 928*a(n-1) - 26942*a(n-2) + 928*a(n-3) - a(n-4).
O.g.f.: 16*x*(4*x^2 -337*x +4)/((x^2 -30*x +1)*(x^2 -898*x +1)). (End)
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MATHEMATICA
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CoefficientList[Series[16*x*(4*x^2 - 337*x + 4)/(x^2 - 30*x + 1)/(x^2 - 898*x + 1), {x, 0, 50}], x] (* G. C. Greubel, Oct 13 2017 *)
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PROG
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(PARI) x='x+O('x^50); concat([0], Vec(16*x*(4*x^2 -337*x +4)/((x^2 -30*x +1)*(x^2 -898*x +1)))) \\ G. C. Greubel, Oct 13 2017
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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