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 A224428 The hyper-Wiener index of the dendrimer NS[n], defined pictorially in the A. R. Ashrafi et al. reference. 1
 1032, 54472, 853256, 8392840, 64852872, 433408392, 2632152456, 14947110280, 80788946312, 420521631112, 2125121035656, 10487138557320, 50753701289352, 241670439050632, 1135046330686856, 5268615489133960, 24208077521689992, 110246366797634952 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS a(1) has been checked by the direct computation of the Wiener index (using Maple). REFERENCES A. R. Ashrafi and M. Mirzargar, The study of an infinite class of dendrimer nanostars by topological index approaches, J. Appl. Math. Comput, 31, 2009, 289-294. M. J. Nadjafi-Arani, A new algorithm for computing the Wiener index of molecular graphs (unpublished paper). LINKS Index entries for linear recurrences with constant coefficients, signature (15,-86,232,-288,128). FORMULA a(n) = 7560 - 64000*4^n*n - 113312*2^n + 106784*4^n + 25600*4^n*n^2. G.f.: 8*(129+4874*x+15616*x^2+4896*x^3)/((1-x)*(1-2*x)*(1-4*x)^3). [Bruno Berselli, Apr 06 2013] MAPLE a := proc (n) options operator, arrow: 7560-113312*2^n+25600*4^n*n^2-64000*4^n*n+106784*4^n end proc: seq(a(n), n = 0 .. 18); MATHEMATICA CoefficientList[Series[8 (129 + 4874 x + 15616 x^2 + 4896 x^3)/((1 - x) (1 - 2 x) (1 - 4 x)^3), {x, 0, 20}], x] (* Bruno Berselli, Apr 06 2013 *) CROSSREFS Cf. A224427. Sequence in context: A023062 A035046 A282357 * A283724 A168225 A282576 Adjacent sequences:  A224425 A224426 A224427 * A224429 A224430 A224431 KEYWORD nonn,easy AUTHOR Emeric Deutsch, Apr 06 2013 STATUS approved

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Last modified May 20 16:35 EDT 2022. Contains 353875 sequences. (Running on oeis4.)