OFFSET
1,1
COMMENTS
a(1) has been checked by the direct computation of the Wiener index (using Maple).
REFERENCES
A. Madanshekaf, The Randic index of some dendrimer nanostars, J. Appl. Math. & Informatics, 29, 2011, 1075-1080.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = 4^n*(31752*n-46494)+2^n*(3276*n+51786)-3996.
G.f.: 36*x*(1310-3099*x+3006*x^2-4520*x^3+2304*x^4)/((1-x)*(1-2*x)^2*(1-4*x)^2).
MAPLE
a := proc (n) options operator, arrow: 4^n*(31752*n-46494)+2^n*(3276*n+51786)-3996 end proc: seq(a(n), n = 1 .. 20);
MATHEMATICA
CoefficientList[Series[36 (1310 - 3099 x + 3006 x^2 - 4520 x^3 + 2304 x^4) / ((1 - x) (1 - 2 x)^2 (1 - 4 x)^2), {x, 0, 20}], x] (* Vincenzo Librandi, Aug 04 2013 *)
PROG
(Magma) [(4^n*(31752*n-46494)+2^n*(3276*n+51786))-3996: n in [1..20]]; // Vincenzo Librandi, Aug 04 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Emeric Deutsch, Aug 03 2013
STATUS
approved