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a(1)=3, a(2)=2, a(n)=3*a(n-1) + 2*a(n-2)
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%I #30 Dec 31 2023 10:23:33

%S 3,2,12,40,144,512,1824,6496,23136,82400,293472,1045216,3722592,

%T 13258208,47219808,168175840,598967136,2133253088,7597693536,

%U 27059586784,96374147424,343241615840,1222473142368,4353902658784,15506654261088,55227768100832

%N a(1)=3, a(2)=2, a(n)=3*a(n-1) + 2*a(n-2)

%H Vincenzo Librandi, <a href="/A189736/b189736.txt">Table of n, a(n) for n = 1..100</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3,2).

%F G.f.: x*(3-7*x)/(1-3*x-2*x^2). - _Bruno Berselli_, May 24 2011

%t LinearRecurrence[{3,2},{3,2},40]

%o (Maxima) a[1]:3$ a[2]:2$ a[n]:=3*a[n-1]+2*a[n-2]$ makelist(a[n], n, 1, 26); /* _Bruno Berselli_, May 24 2011 */

%Y Cf. A000045, A000079, A105476, A159612, A080040, A135522, A103435, A189732, A189734, A189735, A189737, A189738, A189739, A189741, A189742, A189743, A189744, A189745, A189746, A189747, A189748, A189749.

%K nonn,easy

%O 1,1

%A _Harvey P. Dale_, Apr 26 2011