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A227487 The hyper-Wiener index of the nanostar dendrimer defined pictorially as G[n] in the M. H. Khalifeh et al. reference. 1
34255, 398665, 3470157, 25438869, 166187685, 999925445, 5660148997, 30581012869, 159315487365, 806202248325, 3984535138437, 19312921409669, 92094055975045, 433117479708805, 2012917990713477, 9259384642267269, 42212038923118725, 190920673305290885, 857470623117994117, 3827025150533953669 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

a(0) and a(1) have been checked by the direct computation of the Wiener index (using Maple).

REFERENCES

M. K. Khalifeh, H. Yousefi-Azari, A. R. Ashrafi, The Szeged and Wiener numbers of water soluble polyaryl ether dendrimer nanostars, Digest J. Nanomaterials and Biostructures, 4, 2009, 63-66.

LINKS

Table of n, a(n) for n=0..19.

FORMULA

a(n) = -6011+2^n*(-111166-5960*n+7000*n^2)+4^n*(151432-35200*n+40000*n^2).

G.f.: (34255 -252180*z + 1033772*z^2 -2480544*z^3+3259584*z^4-2547712*z^5+790528*z^6)/((1-z)*(1-2*z)^3*(1-4*z)^3).

MAPLE

a := proc (n) options operator, arrow: -6011+2^n*(-111166-5960*n+7000*n^2)+4^n*(151432-35200*n+40000*n^2) end proc: seq(a(n), n = 0 .. 20);

CROSSREFS

Cf. A227486

Sequence in context: A234820 A182292 A206214 * A204411 A238927 A236796

Adjacent sequences:  A227484 A227485 A227486 * A227488 A227489 A227490

KEYWORD

nonn

AUTHOR

Emeric Deutsch, Jul 13 2013

STATUS

approved

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Last modified October 19 15:32 EDT 2021. Contains 348091 sequences. (Running on oeis4.)