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%I #24 Jan 19 2024 09:10:24
%S 1,4,20,104,540,2804,14560,75604,392580,2038504,10585100,54964004,
%T 285405120,1481989604,7695353140,39958755304,207489129660,
%U 1077404403604,5594511147680,29049960142004,150844311857700,783271519430504
%N a(n)=5*a(n-1)+a(n-2), n>2 ; a(0)=1, a(1)=4, a(2)=20 .
%H Paolo Xausa, <a href="/A155181/b155181.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (5,1).
%F G.f.: (1-x-x^2)/(1-5*x-x^2).
%F a(n) = Sum_{k=0..n} A155161(n,k)*4^k. - _Philippe Deléham_, Feb 08 2012
%t LinearRecurrence[{5, 1}, {1, 4, 20}, 25] (* _Paolo Xausa_, Jan 19 2024 *)
%Y Cf. A155161.
%K nonn,easy
%O 0,2
%A _Philippe Deléham_, Jan 21 2009
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