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A221004 The Wiener index of the nanostar dendrimer NS[n], defined pictorially in the Wang-Hua reference. 1
1437, 4263, 15675, 68163, 325779, 1602483, 7835379, 37613427, 176915571, 816731763, 3710601843, 16633811571, 73738101363, 323845964403, 1411137700467, 6107956052595, 26286286307955, 112564798489203, 479941662081651, 2038504721744499, 8628988563948147, 36415869693198963, 153263217907335795, 643451990789063283, 2695404780741722739, 11268007106608890483 (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) = 627 + 2^n*(936*n+1602)+4^n*(432*n-792).
G.f.: 3*(479-4806*x+17408*x^2-25152*x^3+13952*x^4)/((1-x)*(1-2*x)^2*(1-4*x)^2). - Bruno Berselli, Dec 30 2012
MAPLE
a := proc (n) options operator, arrow: 627+2^n*(936*n+1602)+4^n*(432*n-792) end proc: seq(a(n), n = 0 .. 25);
CROSSREFS
Cf. A221005.
Sequence in context: A114083 A143475 A245948 * A204862 A227494 A352249
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Dec 29 2012
STATUS
approved

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Last modified June 20 22:01 EDT 2024. Contains 373532 sequences. (Running on oeis4.)