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A227489
The hyper-Wiener index of the nanostar dendrimer NSC_5C_6[n], defined pictorially in the Ashrafi et al. and the Rostami et al. references.
1
9801, 800545, 14262241, 148766529, 1187870657, 8103701057, 49907422785, 286259766337, 1558851796033, 8161139590209, 41432038278209, 205221516272705, 996243752510529, 4755963555931201, 22386081148494913, 104106406002746433
OFFSET
1,1
COMMENTS
a(2) has been checked by the direct computation of the Wiener index (using Maple).
LINKS
A. R. Ashrafi and P. Nikzad, Szeged index of nanostar dendrimers, Digest J. of Nanomaterials and Biostructures, 4, No. 1, 2009, 155-157.
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.
FORMULA
a(n) = 189505 + 2^(n)*(360*n^(2) - 1148*n - 1285024) + 4^(n)*(129600*n^(2) -627120*n + 1095500).
G.f. = z*(9801 +614326*z +522036*z^2 - 8367736*z^3+6785696*z^4+5562240*z^5-9728*z^6)/((1-z)*(1-2*z)^3*(1-4*z)^3).
MAPLE
a := proc (n) options operator, arrow: 189505+2^n*(360*n^2-1148*n-1285024)+4^n*(129600*n^2-627120*n+1095500) end proc: seq(a(n), n = 1 .. 18);
CROSSREFS
Cf. A227488.
Sequence in context: A069333 A222814 A156735 * A350918 A113937 A036353
KEYWORD
nonn
AUTHOR
Emeric Deutsch, Jul 16 2013
STATUS
approved