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A143367
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The Szeged index of third type dendrimer nanostar which has grown n stages.
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1
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9412, 30652, 123148, 564844, 2726572, 13219372, 63206188, 296679724, 1368005932, 6210491692, 27825661228, 123303445804, 541361800492, 2358354445612, 10205728212268, 43913619703084, 188020440958252, 801552290809132, 3404105445803308, 14408036898571564
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OFFSET
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1,1
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LINKS
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FORMULA
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a(n) = 3636*2^n + 1324 + 720*n*4^n + 1560*n*2^n - 1296*4^n.
G.f.: -4*x*(58624*x^4-116832*x^3+81760*x^2-22926*x+2353) / ((x-1)*(2*x-1)^2*(4*x-1)^2). - Colin Barker, Sep 20 2013
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MAPLE
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a:=3636*2^n+1324+720*n*4^n+1560*n*2^n-1296*4^n: seq(a(n), n=1..18);
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MATHEMATICA
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LinearRecurrence[{13, -64, 148, -160, 64}, {9412, 30652, 123148, 564844, 2726572}, 30] (* Harvey P. Dale, Aug 20 2019 *)
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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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EXTENSIONS
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STATUS
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approved
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