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(n^3+n)*3^n.
1

%I #13 Sep 08 2022 08:45:27

%S 6,90,810,5508,31590,161838,765450,3411720,14526054,59639490,

%T 237731274,924707340,3523453830,13191428502,48642794730,177008116752,

%U 636661003590,2266409860650,7994034370026,27964010896020,97092998430246

%N (n^3+n)*3^n.

%H Vincenzo Librandi, <a href="/A121607/b121607.txt">Table of n, a(n) for n = 1..1000</a>

%F G.f.: 6*x*(1 + 3*x + 9*x^2)/(1 - 3*x)^4. - _Vincenzo Librandi_, Feb 22 2013

%t Table[(n^3 + n)*3^n, {n, 30}] (* or *) CoefficientList[Series[6 (1 + 3 x + 9 x^2)/(1 - 3 x)^4, {x, 0, 30}], x] (* _Vincenzo Librandi_, Feb 22 2013 *)

%o (Magma) [(n^3 + n)*3^n: n in [1..30]]; // _Vincenzo Librandi_, Feb 22 2013

%Y Cf. A128796, A128960, A128985, A129002.

%K nonn,easy

%O 1,1

%A _Mohammad K. Azarian_, May 02 2007