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A227699 The Wiener index of the nanostar dendrimer defined pictorially in the Ashrafi et al. reference. 1
34081, 133753, 606505, 2879881, 13759561, 65105353, 303499465, 1393200841, 6306020041, 28195082953, 124751348425, 547085017801, 2381092856521, 10296337572553, 44275297821385, 189465493250761, 807328896525001, 3427204095550153 (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).

LINKS

Table of n, a(n) for n=0..17.

A. R. Ashrafi, A. Karbasioun, and M. V. Diudea, Computing Wiener and detour indices of a new type of nanostar dendrimers, MATCH Commun. Math. Comput. Chem. 65, 2011, 193-200.

FORMULA

a(n) = 8905 + 2^(n)*(10560*n + 21528) + 4^(n)*(11520*n + 3648). Replacing n with n+1, we obtain the expression given in Theorem 1 of the Ashrafi et al. reference.

G.f.: (34081 - 309300*x + 1048900*x^2 - 1488480*x^3 + 794944*x^4)/((1-x)*(1-2*x)^2*(1-4*x)^2).

MAPLE

a := proc (n) options operator, arrow: 8905+2^n*(10560*n+21528)+4^n*(11520*n+3648) end proc: seq(a(n), n = 0 .. 22);

CROSSREFS

Cf. A227700.

Sequence in context: A231196 A212229 A204669 * A234820 A182292 A206214

Adjacent sequences:  A227696 A227697 A227698 * A227700 A227701 A227702

KEYWORD

nonn

AUTHOR

Emeric Deutsch, Jul 21 2013

STATUS

approved

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Last modified August 8 05:50 EDT 2020. Contains 336290 sequences. (Running on oeis4.)