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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
OFFSET
0,1
COMMENTS
a(0) and a(1) have been checked by the direct computation of the Wiener index (using Maple).
LINKS
M. K. Khalifeh, H. Yousefi-Azari, and A. R. Ashrafi, The Szeged and Wiener numbers of water soluble polyaryl ether dendrimer nanostars, Digest J. Nanomaterials and Biostructures, 4, 2009, 63-66.
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
Sequence in context: A234820 A182292 A206214 * A204411 A238927 A236796
KEYWORD
nonn
AUTHOR
Emeric Deutsch, Jul 13 2013
STATUS
approved