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%I #33 Feb 18 2024 03:32:50
%S 3,4,24,88,360,1432,5736,22936,91752,367000,1468008,5872024,23488104,
%T 93952408,375809640,1503238552,6012954216,24051816856,96207267432,
%U 384829069720,1539316278888,6157265115544,24629060462184,98516241848728,394064967394920
%N a(1)=3, a(2)=4, a(n) = 3*a(n-1) + 4*a(n-2).
%H Vincenzo Librandi, <a href="/A189738/b189738.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 (3,4).
%F G.f.: x*(3-5*x)/(1-3*x-4*x^2). - _Bruno Berselli_, May 24 2011
%t LinearRecurrence[{3,4},{3,4},40]
%o (Maxima) a[1]:3$ a[2]:4$ a[n]:=3*a[n-1]+4*a[n-2]$ makelist(a[n], n, 1, 25); /* _Bruno Berselli_, May 24 2011 */
%o (PARI) a(n)=7<<(2*n)\/20-2*(-1)^n \\ _Charles R Greathouse IV_, Jul 15 2011
%Y Cf. A201455.
%K nonn,easy
%O 1,1
%A _Harvey P. Dale_, Apr 26 2011