A221013 - OEIS

%I #11 Mar 29 2019 04:55:24

%S 3722,180552,2683436,25503780,192352212,1262648052,7564190516,

%T 42499015860,227766985652,1177463868852,5916913295796,29062281058740,

%U 140094358522292,664827881302452,3113397432740276,14415083971242420,66086948110494132,300376858346940852,1354914339889899956

%N The hyper-Wiener index of the nanostar dendrimer G_n , defined pictorially in the Golriz - Darafsheh - Khalifeh reference.

%H M. Golriz, M. R. Darafsheh, and M. H. Khalifeh, <a href="http://chalcogen.ro/1545_Golriz.pdf">The Wiener, Szeged and PI-indices of a phenylazomethine dendrimer</a>, Digest J. Nanomaterials and Biostructures, 6, No. 4, 2011, 1545-1549.

%F a(n) = 27060 + 2^n*(-4550*n^2 +16990*n -243062) + 4^n*(67600*n^2-133640*n+219724).

%F G.f.: 2*(1861+54917*x-94376*x^2-382948*x^3+635520*x^4+150336*x^5)/((1-x)*(1-2*x)^3*(1-4*x)^3). - _Bruno Berselli_, Dec 30 2012

%p a := proc (n) options operator, arrow: 27060+2^n*(-4550*n^2+16990*n-243062)+4^n*(67600*n^2-133640*n+219724) end proc: seq(a(n), n = 0 .. 18);

%Y Cf. A221012.

%K nonn,easy

%O 0,1

%A _Emeric Deutsch_, Dec 29 2012