A224466 - OEIS

A224466

The hyper-Wiener index of the nanostar dendrimer defined pictorially as NS[n] in the Z. S. Irani reference.

27180, 47750, 149614, 608478, 2894430, 15765790, 91789854, 535578398, 3038252830, 16628755230, 87950187294, 451486444318, 2259819129630, 11073313975070, 53298037467934, 252671079230238, 1182401611180830, 5471588447169310, 25074506044287774, 113930988546960158, 513775960055622430

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,1

REFERENCES

Z. S. Irani, A. Karbasioun, Wiener index of a new type of nanostar dendrimer, Iranian J. Math. Chem., 2, 2011, 79-85.

LINKS

Table of n, a(n) for n=0..20.

FORMULA

a(n) = 11038 + 2^n*(7000*n^2 -8060*n - 3132)+4^n*(1600*n^2 - 9600*n + 19274).

G.f.: 2*(13590 - 234335*z + 1659682*z^2 - 6179084*z^3 + 12903624*z^4 - 14317312*z^5 + 6302848*z^6)/((1-z)*(1-2*z)^3*(1-4*z)^3).

MAPLE

a := proc (n) options operator, arrow: 11038+2^n*(7000*n^2-8060*n-3132)+4^n*(1600*n^2-9600*n+19274) end proc: seq(a(n), n = 0 .. 20);