OFFSET
0,1
COMMENTS
a(1) has been checked by the direct computation of the Wiener index (using Maple).
REFERENCES
A. R. Ashrafi and M. Mirzargar, The study of an infinite class of dendrimer nanostars by topological index approaches, J. Appl. Math. Comput, 31, 2009, 289-294.
M. J. Nadjafi-Arani, A new algorithm for computing the Wiener index of molecular graphs (unpublished paper).
LINKS
Index entries for linear recurrences with constant coefficients, signature (11,-42,64,-32).
FORMULA
a(n) = -1113 + 8112*2^n - 6656*4^n + 5120*n*4^n.
G.f.: (343+5194*x+4448*x^2+32*x^3)/((1-x)*(1-2*x)*(1-4*x)^2). [Bruno Berselli, Apr 06 2013]
MAPLE
a := proc (n) options operator, arrow: -1113+8112*2^n+5120*4^n*n-6656*4^n end proc: seq(a(n), n = 0 .. 18);
MATHEMATICA
CoefficientList[Series[(343 + 5194 x + 4448 x^2 + 32 x^3)/((1 - x) (1 - 2 x) (1 - 4 x)^2), {x, 0, 20}], x] (* Bruno Berselli, Apr 06 2013 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Apr 06 2013
STATUS
approved