A143367 - OEIS

%I #15 Aug 20 2019 15:13:09

%S 9412,30652,123148,564844,2726572,13219372,63206188,296679724,

%T 1368005932,6210491692,27825661228,123303445804,541361800492,

%U 2358354445612,10205728212268,43913619703084,188020440958252,801552290809132,3404105445803308,14408036898571564

%N The Szeged index of third type dendrimer nanostar which has grown n stages.

%H A. Iranmanesh and N. Gholami, <a href="https://doi.org/10.1049/mnl:20070057">Computing the Szeged index of third and fourth dendrimer nanostars</a>, Micro & Nano Letters, 2 (2007), 107-110.

%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) = 3636*2^n + 1324 + 720*n*4^n + 1560*n*2^n - 1296*4^n.

%F G.f.: -4*x*(58624*x^4-116832*x^3+81760*x^2-22926*x+2353) / ((x-1)*(2*x-1)^2*(4*x-1)^2). - _Colin Barker_, Sep 20 2013

%p a:=3636*2^n+1324+720*n*4^n+1560*n*2^n-1296*4^n: seq(a(n),n=1..18);

%t LinearRecurrence[{13,-64,148,-160,64},{9412,30652,123148,564844,2726572},30] (* _Harvey P. Dale_, Aug 20 2019 *)

%Y Cf. A143369.

%K nonn,easy

%O 1,1

%A _Emeric Deutsch_, Sep 05 2008

%E More terms from _Colin Barker_, Sep 20 2013