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
KEYWORD
nonn
AUTHOR
Emeric Deutsch, Jul 16 2013
STATUS
approved