%I #12 Dec 20 2024 15:31:50
%S 1,3,12,47,183,714,2785,10863,42372,165275,644667,2514570,9808261,
%T 38257827,149227404,582072215,2270414511,8855914986,34543132921,
%U 134737972743,525555146964,2049965624963,7996038261267,31189121952618,121655411891581,474525678055131
%N Expansion of 1/(1-3*x-3*x^2-2*x^3).
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,3,2).
%F G.f.: 1/(1-3*x-3*x^2-2*x^3).
%F a(n) = 3*a(n-1) + 3*a(n-2) + 2*a(n-3). - _Wesley Ivan Hurt_, Jan 20 2024
%t CoefficientList[Series[1/(1 - 3*x - 3*x^2 - 2*x^3), {x, 0, 30}], x] (* _Wesley Ivan Hurt_, Jan 20 2024 *)
%t LinearRecurrence[{3,3,2},{1,3,12},30] (* _Harvey P. Dale_, Dec 20 2024 *)
%o (PARI) Vec(1/(1-3*x-3*x^2-2*x^3)+O(x^99)) \\ _Charles R Greathouse IV_, Sep 27 2012
%Y Partial sums of S(n, x), for x=1...14, A021823, A000217, A027941, A061278, A089817, A053142, A092521, A076765, A092420, A097784, A097826-A097828, A076139.
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, Nov 17 2002