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a(n) = (12*n)^3.
2

%I #27 Oct 18 2024 17:27:29

%S 0,1728,13824,46656,110592,216000,373248,592704,884736,1259712,

%T 1728000,2299968,2985984,3796416,4741632,5832000,7077888,8489664,

%U 10077696,11852352,13824000,16003008,18399744,21024576,23887872,27000000,30371328,34012224

%N a(n) = (12*n)^3.

%H Vincenzo Librandi, <a href="/A017523/b017523.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).

%F G.f.: 1728*x*(1 + 4*x + x^2)/(1 - x)^4. - _Vincenzo Librandi_, Jul 05 2014

%F a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>3. - _Vincenzo Librandi_, Jul 05 2014

%t Table[1728 n^3, {n, 0, 40}] (* or *) CoefficientList[Series[1728 x (1 + 4 x + x^2)/(1 - x)^4, {x, 0, 40}], x] (* _Vincenzo Librandi_, Jul 05 2014 *)

%o (Maxima) makelist((12*n)^3,n,0,30); /* _Martin Ettl_, Oct 21 2012 */

%o (Magma) [1728*n^3: n in [0..40]]; // _Vincenzo Librandi_, Jul 05 2014

%o (Magma) I:=[0,1728,13824, 46656]; [n le 4 select I[n] else 4*Self(n-1)-6*Self(n-2)+4*Self(n-3)-Self(n-4): n in [1..40]]; // _Vincenzo Librandi_, Jul 05 2014

%Y Cf. similar sequences listed in A244725.

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_