%I #33 May 23 2018 10:53:00

%S 136,244,460,892,1756,3484,6940,13852,27676,55324,110620,221212,

%T 442396,884764,1769500,3538972,7077916,14155804,28311580,56623132,

%U 113246236,226492444,452984860,905969692,1811939356,3623878684,7247757340,14495514652,28991029276,57982058524

%N a(n) = 54*2^n + 28 (n >= 1).

%C a(n) is the number of edges of the nanostar dendrimer G[n] from the Ashrafi et al. reference.

%H Colin Barker, <a href="/A304606/b304606.txt">Table of n, a(n) for n = 1..1000</a>

%H A. R. Ashrafi, A. Karbasioun, and M. V. Diudea, <a href="http://match.pmf.kg.ac.rs/electronic_versions/Match65/n1/match65n1_193-200.pdf">Computing Wiener and detour indices of a new type of nanostar dendrimers</a>, MATCH Commun. Math. Comput. Chem. 65, 2011, 193-200.

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3,-2).

%F From _Michael De Vlieger_, May 16 2018: (Start)

%F G.f.: 4*x*(34 - 41*x)/(1 - 3*x + 2*x^2).

%F a(n) = 3*a(n - 1) - 2*a(n - 2) for n > 2. (End)

%p seq(54*2^n+28, n = 1 .. 40);

%t CoefficientList[Series[4 (34 - 41 x)/(1 - 3 x + 2 x^2), {x, 0, 33}], x] (* or *)

%t LinearRecurrence[{3, -2}, {136, 244}, 34] (* or *)

%t Array[54*2^# + 28 &, 34] (* _Michael De Vlieger_, May 16 2018 *)

%o (PARI) a(n) = 54*2^n + 28; \\ _Altug Alkan_, May 15 2018

%o (PARI) Vec(4*x*(34 - 41*x)/(1 - 3*x + 2*x^2) + O(x^40)) \\ _Colin Barker_, May 23 2018

%o (GAP) List([1..40],n->54*2^n+28); # _Muniru A Asiru_, May 16 2018

%Y Cf. A304605, A304607, A304608.

%K nonn,easy

%O 1,1

%A _Emeric Deutsch_, May 15 2018