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%I #12 Feb 18 2017 18:47:52
%S 1,6,27,135,648,3159,15309,74358,360855,1751787,8503056,41275251,
%T 200353257,972537030,4720790403,22915204479,111232727064,539935021503,
%U 2620899608085,12722114017782,61754438526111,299762341738371,1455076971950112,7063091991495675
%N a(n) = 3^n*F(n+2).
%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (3,9).
%F G.f.: (1+3x)/(1-3x-9x^2)=1/(-3x-1/(-3x-1)).
%F a(n) = (1/2+3*sqrt(5)/10)*(3/2+3*sqrt(5)/2)^n+(1/2-3*sqrt(5)/10)*(3/2-3*sqrt(5)/2)^n.
%t Table[3^n Fibonacci[n+2],{n,0,30}] (* or *) LinearRecurrence[{3,9},{1,6},30] (* _Harvey P. Dale_, May 23 2014 *)
%Y Cf. A000045.
%K easy,nonn
%O 0,2
%A _Paul Barry_, Mar 24 2010
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