%I #17 Sep 08 2022 08:44:57

%S 1,17,58,160,408,1000,2392,5624,13048,29944,68088,153592,344056,

%T 765944,1695736,3735544,8191992,17891320,38928376,84410360,182452216,

%U 393215992,845152248,1811939320,3875536888,8271167480,17616076792

%N a(n) = T(3,n), array T given by A048505.

%C n-th difference of a(n), a(n-1), ..., a(0) is (16, 25, 36, 49, 64, ...).

%H Vincenzo Librandi, <a href="/A048508/b048508.txt">Table of n, a(n) for n = 0..2000</a>

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (7,-18,20,-8).

%F a(n) = (n+4)*(n+9) * 2^(n-2) - 8. - _Ralf Stephan_, Feb 05 2004

%F a(n) = 7*a(n-1)-18*a(n-2)+20*a(n-3)-8*a(n-4). - _Colin Barker_, Feb 25 2015

%F G.f.: (40*x^3-43*x^2+10*x+1) / ((x-1)*(2*x-1)^3). - _Colin Barker_, Feb 25 2015

%o (Magma) [(n+4)*(n+9) * 2^(n-2) - 8: n in [0..30]]; // _Vincenzo Librandi_, Sep 26 2011

%o (PARI) Vec((40*x^3-43*x^2+10*x+1) / ((x-1)*(2*x-1)^3) + O(x^100)) \\ _Colin Barker_, Feb 25 2015

%K nonn,easy

%O 0,2

%A _Clark Kimberling_