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A224462 The hyper-Wiener index of Wang's helicene-based dendrimer defined pictorially as DNS_2[n] in the Shabani et al. reference. 1

%I

%S 5150,279882,4912058,52877106,437291570,3075863058,19424101394,

%T 113690358162,629297936786,3338556446610,17134277121938,

%U 85638400421778,418886606368658,2012591878934418,9525395433164690,44509034884173714,205695168792825746

%N The hyper-Wiener index of Wang's helicene-based dendrimer defined pictorially as DNS_2[n] in the Shabani et al. reference.

%D H. Shabani, A. R. Ashrafi, I. Gutman, Geometric-arithmetic index: an algebraic approach, Studia UBB, Chemia, LV, 2010, 107-112.

%F a(n) = -61550 + 2^n*(30861*n^2 - 164298*n - 602830)+4^n*(59049*n^2 - 677241*n/2 + 664380).

%F G.f.: 2*x*(2575+91016*x+183400*x^2-872548*x^3-267848*x^4+32480*x^5) / ((1-x)*(1-2*x)^3*(1-4*x)^3).

%p a := proc (n) options operator, arrow: -61550+2^n*(30861*n^2-164298*n-602830)+4^n*(59049*n^2-(677241/2)*n+664380) end proc: seq(a(n), n = 1 .. 17);

%Y Cf. A224461.

%K nonn,easy

%O 1,1

%A _Emeric Deutsch_, Jul 12 2013

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Last modified May 17 12:55 EDT 2021. Contains 343971 sequences. (Running on oeis4.)