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A224434 The hyper-Wiener index of the dendrimer D_3[n], defined pictorially in the A. R. Ashrafi et al. reference. 1
357, 112311, 2540727, 28861191, 239301927, 1663126311, 10343555367, 59654395431, 325892779047, 1709482140711, 8689254356007, 43074112914471, 209214647804967, 999137244521511, 4704103526212647, 21880432615990311, 100713104634651687, 459359353571484711 (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 hyper-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..17.

FORMULA

a(n) = 107559 - 551400*2^n + 108900*4^n*n^2 + 444198*4^n -304590*4^n*n + 74910*2^n*n - 18150*2^n*n^2.

G.f. = 3(119+35176z+153456z^2-931008z^3+391824z^4+1360960z^5-42496z^6)/[(1-z)(1-2z)^3(1-4z)^3].

MAPLE

a := proc (n) options operator, arrow: 107559-551400*2^n + 108900*4^n*n^2 + 444198*4^n - 304590*4^n*n + 74910*2^n*n - 18150*2^n*n^2 end proc: seq(a(n), n = 0 .. 17);

CROSSREFS

Cf. A224433

Sequence in context: A241931 A166916 A166913 * A278412 A278632 A108875

Adjacent sequences:  A224431 A224432 A224433 * A224435 A224436 A224437

KEYWORD

nonn

AUTHOR

Emeric Deutsch, Apr 06 2013

STATUS

approved

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Last modified June 13 00:57 EDT 2021. Contains 344980 sequences. (Running on oeis4.)