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%I #18 Sep 08 2022 08:45:30
%S 0,9,648,19683,419904,7381125,114791256,1640558367,22039921152,
%T 282429536481,3486784401000,41768190339579,488038239039168,
%U 5584479224838813,62773918496412984,694882570819440375
%N n^3*9^n.
%H Vincenzo Librandi, <a href="/A128795/b128795.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (36,-486,2916,-6561).
%F G.f.: 9*x*(1+36*x+81*x^2)/(1-9*x)^4. [_R. J. Mathar_, Dec 19 2008]
%F a(n) = 36*a(n-1) -486*a(n-2) +2916*a(n-3) -6561*a(n-4). - _Vincenzo Librandi_, Feb 10 2013
%t CoefficientList[Series[9 x (1 + 36 x + 81 x^2)/(1 - 9 x)^4, {x, 0, 30}], x] (* _Vincenzo Librandi_, Feb 10 2013 *)
%o (Magma) [n^3*9^n: n in [0..20]]; // _Vincenzo Librandi_, Feb 10 2013
%Y Cf. A036289, A007758.
%K nonn,easy
%O 0,2
%A _Mohammad K. Azarian_, Apr 07 2007
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