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A221006 The Wiener index of the nanostar dendrimer NS[n], defined pictorially in the Karbasioun-Ashrafi-Diudea reference. 1
1296, 14526, 107082, 649890, 3539538, 18027954, 87813234, 414505458, 1911928050, 8665131762, 38733797106, 171235454706, 750157258482, 3261519544050, 14089697722098, 60533384085234, 258832139157234, 1102123427954418, 4675674117242610, 19771419930918642, 83360577251966706 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
LINKS
A. Karbasioun, A. R. Ashrafi, and M. V. Diudea, Distance and detour matrices of an infinite class of dendrimer nanostars, MATCH Commun. Math. Comput. Chem. 63, 2010, 239-246.
FORMULA
a(n) = -270 + 2^n*3510+4^n*(3888*n-1944) (see Theorem 1 in the Karbasioun-Ashrafi-Diudea reference).
G.f.: -54*(16*x^3-32*x^2-5*x-24) / ((x-1)*(2*x-1)*(4*x-1)^2). [Colin Barker, Jan 01 2013]
MAPLE
a := proc (n) options operator, arrow: -270+3510*2^n+4^n*(3888*n-1944) end proc: seq(a(n), n = 0 .. 20);
CROSSREFS
Cf. A221007.
Sequence in context: A137488 A189991 A250438 * A016864 A064785 A223560
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Dec 29 2012
STATUS
approved

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Last modified June 20 18:51 EDT 2024. Contains 373532 sequences. (Running on oeis4.)