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A227486 The Wiener index of the nanostar dendrimer defined pictorially as G[n] in the M. H. Khalifeh et al. reference. 2
5298, 39854, 251046, 1422550, 7507638, 37673334, 182185206, 856903670, 3945369078, 17864129014, 79813259766, 352738009590, 1545019376118, 6716624699894, 29013289140726, 124641612792310, 532923049312758, 2269124503273974, 9626239798084086, 40703952922083830, 171611842722922998 (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

Matthew House, Table of n, a(n) for n = 0..1640

Index entries for linear recurrences with constant coefficients, signature (13,-64,148,-160,64).

FORMULA

a(n) = 502 + 2^(n)*(2800*n + 8716) + 4^(n)*(8000*n - 3920).

G.f.: 2*(2649 - 14510*z + 36008*z^2 - 37248*z^3 + 15360*z^4)/((1-z)*(1-2*z)^2*(1-4*z)^2).

a(n) = 13*a(n-1) - 64*a(n-2) + 148*a(n-3) - 160*a(n-4) + 64*a(n-5). - Matthew House, Nov 01 2016

MAPLE

a := proc (n) options operator, arrow: 502+2^n*(2800*n+8716)+4^n*(8000*n-3920) end proc: seq(a(n), n = 0 .. 20);

CROSSREFS

Cf. A227487

Sequence in context: A178027 A053397 A300365 * A252189 A204838 A212078

Adjacent sequences:  A227483 A227484 A227485 * A227487 A227488 A227489

KEYWORD

nonn

AUTHOR

Emeric Deutsch, Jul 13 2013

STATUS

approved

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Last modified March 1 02:43 EST 2021. Contains 341732 sequences. (Running on oeis4.)