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A123393
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Values X satisfying the equation 7(X-Y)^4-2XY=0, where X>=Y.
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2
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0, 32, 27000, 24193888, 21724523760, 19508551374752, 17518656008529000, 15731733545110199008, 14127079203594427607520, 12686101393056537201642272, 11392104923884436660778375000
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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, 28, 26880, 24190292, 21724416000, ...
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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) = 2 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.: 8*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[8*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(8*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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