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A221050
The Wiener index of the nanostar dendrimer D_1[n], defined pictorially in the Eslahchi et al. reference.
1
42, 1008, 10276, 75180, 462140, 2558556, 13231260, 65284380, 311431708, 1448846364, 6612207644, 29725724700, 132031520796, 580686331932, 2533085184028, 10973912563740, 47262391730204, 202517499871260, 863943782826012, 3671274602627100, 15547105441480732
OFFSET
0,1
REFERENCES
Ch. Eslahchi, S. Alikhani, M. H. Akhbari, Hosoya polynomial of an infinite family of dendrimer nanostar, Iranian J. Math. Chem. 2 (2011) 71-79.
FORMULA
a(n) = 28+2^n*(448*n+1554)+4^n*(784*n-1540). Theorem 5 of the Eslahchi et al. paper contains a less explicit formula for the Wiener index.
G.f.: 14*(3+33*x-10*x^2-8*x^3)/((1-x)*(1-2*x)^2*(1-4*x)^2). - Bruno Berselli, Dec 30 2012
MAPLE
a := proc (n) options operator, arrow: 28+2^n*(448*n+1554)+4^n*(784*n-1540) end proc: seq(a(n), n = 0 .. 20);
CROSSREFS
Cf. A221051.
Sequence in context: A020932 A264489 A036400 * A050988 A163741 A140404
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Dec 30 2012
EXTENSIONS
Offset changed from 1 to 0 by Bruno Berselli, Dec 30 2012
STATUS
approved