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%I #14 Jul 22 2022 11:33:44
%S 666,10854,91062,586278,3293478,17076582,84106854,399946086,
%T 1854359910,8436473190,37822942566,167600700774,735637781862,
%U 3203485138278,13857655946598,59605426371942,255120762469734,1087278900313446,4616298106453350,19533920370425190
%N The Wiener index of the dendrimer G_n , defined pictorially in the Ashrafi - Shabani - Diudea reference.
%H A. R. Ashrafi, H. Shabani, M. V. Diudea, <a href="http://match.pmf.kg.ac.rs/electronic_versions/Match69/n1/match69n1_151-158.pdf">Balaban index of dendrimers</a>, MATCH, Commun. Math. Comput. Chem. 69, 2013, 151-158.
%H <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (13,-64,148,-160,64)
%F a(n) = -666 +2^n*(-270*n+2340) +4^n*(972*n-1674).
%F G.f.: 18*x*(37+122*x-412*x^2-80*x^3)/((1-x)*(1-2*x)^2*(1-4*x)^2). - _Bruno Berselli_, Dec 30 2012
%p a := proc (n) options operator, arrow: -666+2^n*(-270*n+2340)+4^n*(972*n-1674) end proc: seq(a(n), n = 1 .. 20);
%Y Cf. A221015.
%K nonn,easy
%O 1,1
%A _Emeric Deutsch_, Dec 29 2012