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A216122
The Wiener index of the nanostar dendrimer NS[n], defined pictorially in the Ashrafi et al. reference.
1
94698, 1317858, 10315218, 63835698, 349594098, 1781094258, 8661794418, 40799683698, 187793424498, 849479276658, 3790907541618, 16734956611698, 73223518070898, 318024922835058, 1372613885896818, 5892491154499698, 25178059222493298, 107144508620089458
OFFSET
1,1
COMMENTS
a(1) has been checked by the direct computation of the Wiener index (using Maple).
LINKS
A. R. Ashrafi and M. Mirzagar, PI, Szeged and edge Szeged indices of an infinite family of nanostar dendrimers, Indian J. of Chemistry, 47A, 2008, 538-541.
M. Rostami, M. Shabanian, and H. Moghanian, Some topological indices for theoretical study of two types of nanostar dendrimers, Digest J. of Nanomaterials and Biostructures, 7, No. 1, 2012, 247-252.
J. Yang, F. Xia, and S. Chen, Second-order and third-order connectivity indices of an infinite family of dendrimer nanostars, Int. J. Contemp. Math. Sciences, 6, 2011, No. 5, 215-220.
FORMULA
a(n) = -55182 + 181020*2^n - 125640*4^n -42000*n*2^n +93600*n*4^n.
G.f.: -6*x*(2112*x^4+10912*x^3-126044*x^2+14464*x+15783) / ((x-1)*(2*x-1)^2*(4*x-1)^2). - Colin Barker, Apr 01 2013
MAPLE
a := proc (n) options operator, arrow: -55182+181020*2^n-125640*4^n+93600*4^n*n-42000*2^n*n end proc: seq(a(n), n = 1 .. 18);
CROSSREFS
Cf. A216123.
Sequence in context: A252323 A030091 A128376 * A206411 A128389 A258420
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Mar 25 2013
STATUS
approved