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A224453
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The hyper-Wiener index of the nanostar dendrimer NS_2[n], defined pictorially in the A. R. Ashrafi et al. reference.
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1
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477, 14517, 192133, 1790789, 13716357, 92392837, 568494213, 3272754309, 17914312837, 94292506757, 481127721093, 2394073245829, 11669512054917, 55910670854277, 264011366000773, 1231270134409349, 5680970473662597, 25967383211403397, 117723243179141253
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OFFSET
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0,1
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COMMENTS
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a(2) and a(3) have been checked by the direct computation of the Wiener index (using Maple).
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REFERENCES
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A. R. Ashrafi and P. Nikzad, Kekulé index and bounds of energy for nanostar dendrimers, Digest J. of Nanomaterials and Biostructures, 4, No. 2, 2009, 383-388.
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LINKS
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FORMULA
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a(n) = -6011 + (-36208 - 9720n + 2800n^2)*2^n + (42696 -22400n + 6400n^2)*4^n.
G.f.: (477 + 5454z - 12140z^2 + 14440z^3 + 22624z^4 - 202880z^5 + 9728z^6)/((1-z)(1-2z)^3*(1-4z)^3).
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MAPLE
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a := proc (n) options operator, arrow: -6011-22400*4^n*n-9720*2^n*n-36208*2^n+42696*4^n+2800*2^n*n^2+6400*4^n*n^2 end proc: seq(a(n), n = 0 .. 18);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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