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A224431 The Wiener index of the dendrimer D_2[n], defined pictorially in the A. R. Ashrafi et al. reference. 1

%I

%S 224,4878,46250,322146,1914578,10351026,52620146,256370418,1211362802,

%T 5594160114,25382926322,113581912050,502582927346,2203470381042,

%U 9586688622578,41438522310642,178122308583410,761964546228210,3245764578377714

%N The Wiener index of the dendrimer D_2[n], defined pictorially in the A. R. Ashrafi et al. reference.

%C a(2) has been checked by the direct computation of the Wiener index (using Maple).

%D A. R. Ashrafi and H. Shabani, Computing Padmakar-Ivan index of four classes of dendrimers, Bulgarian Chem. Comm., 44, No. 2, 2012, 127-130.

%F a(n) = -14+4846*2^n+1056*2^n*n+2880*4^n*n-4608*4^n.

%F G.f. = 2(112+983z-1414z^2-32z^3+288z^4)/[(1-z)(1-2z)^2(1-4z)^2].

%p a := proc (n) options operator, arrow: -14+4846*2^n+1056*2^n*n+2880*4^n*n-4608*4^n end proc: seq(a(n), n = 0 .. 18);

%Y Cf. A224432

%K nonn

%O 0,1

%A _Emeric Deutsch_, Apr 06 2013

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Last modified May 26 07:48 EDT 2022. Contains 354077 sequences. (Running on oeis4.)