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A224433 The Wiener index of the dendrimer D_3[n], defined pictorially in the A. R. Ashrafi et al. reference. 1
174, 22734, 299646, 2332398, 14462574, 79461294, 406098606, 1980213678, 9348000174, 43104718254, 195270696366, 872477232558, 3855431404974, 16883645533614, 73381802986926, 316914939973038, 1361207885548974, 5819017520467374, 24772799043194286 (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

A. R. Ashrafi and H. Shabani, Computing Padmakar-Ivan index of four classes of dendrimers, Bulgarian Chem. Comm., 44, N0. 2, 2012, 127-130.

LINKS

Table of n, a(n) for n=0..18.

FORMULA

a(n)=-12882+44604*2^n-31548*4^n+21780*n*4^n-7260*n*2^n.

G.f.=(6*(29+3412*z+2540*z^2-22296*z^3-3008*z^4))/[(1-z)*(1-2*z)^2*(1-4*z)^2]

MAPLE

a := proc (n) options operator, arrow: -12882+44604*2^n-31548*4^n+21780*4^n*n-7260*2^n*n end proc: seq(a(n), n = 0 .. 18);

CROSSREFS

Cf. A224434

Sequence in context: A248458 A053173 A185525 * A213866 A252717 A187425

Adjacent sequences:  A224430 A224431 A224432 * A224434 A224435 A224436

KEYWORD

nonn

AUTHOR

Emeric Deutsch, Apr 06 2013

STATUS

approved

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Last modified May 27 03:13 EDT 2022. Contains 354093 sequences. (Running on oeis4.)