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A221005 The hyper-Wiener index of the nanostar dendrimer NS[n], defined pictorially in the Wang-Hua reference. 1
4797, 18800, 88530, 500582, 3112014, 19362974, 115754814, 659875454, 3602117886, 18956429822, 96789115902, 482029987838, 2351490682878, 11274381991934, 53269435990014, 248554431348734, 1147271095058430, 5245861041405950, 23788748016975870, 107088865925791742, 478941290597187582 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
LINKS
H. Wang and H. Hua, Computing the second- and third- connectivity index of an infinite class of dendrimer nanostars, Digest J. Nanomaterials and Biostructures, 5 (2010) 497-502.
L. Yang and H. Hua, Modified terminal Wiener index of a type of dendrimer nanostars, Optoelectronics and Advanced Materials - Rapid Communications, 5 (2011) 160-163.
FORMULA
a(n) = -2+2^n*(1404*n^2+1764*n-3115)+4^n*(1296*n^2-4536*n+7914).
G.f.: (4797-72343*x+450880*x^2-1412380*x^3+2406976*x^4-2246848*x^5+868864*x^6)/((1-x)*(1-2*x)^3*(1-4*x)^3). - Bruno Berselli, Dec 30 2012
MAPLE
a := proc (n) options operator, arrow: -2+2^n*(1404*n^2+1764*n-3115)+4^n*(1296*n^2-4536*n+7914) end proc: seq(a(n), n = 0 .. 20);
CROSSREFS
Cf. A221004.
Sequence in context: A296812 A251775 A096517 * A227495 A254035 A255412
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Dec 29 2012
STATUS
approved

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Last modified June 17 07:23 EDT 2024. Contains 373433 sequences. (Running on oeis4.)