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%I #24 May 18 2019 08:29:07
%S 1,1,5,6,7,12,18,25,37,55,80,117,172,252,369,541,793,1162,1703,2496,
%T 3658,5361,7857,11515,16876,24733,36248,53124,77857,114105,167229,
%U 245086,359191,526420,771506,1130697
%N a(n) = a(n-1) + a(n-3), with a(0) = a(1) = 1, a(2) = 5.
%H G. C. Greubel, <a href="/A011761/b011761.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,1).
%F G.f.: (1+4*x^2)/(1-x-x^3). - _G. C. Greubel_, May 01 2017 [Corrected by _Georg Fischer_, May 18 2019]
%t a[0] := 1; a[1] := 1; a[2] = 5; a[n_] := a[n] =a[n - 1] + a[n - 3]; Table[a[n], {n, 50}] (* _Alonso del Arte_, Dec 05 2011 *)
%t LinearRecurrence[{1,0,1},{1,1,5},40] (* _Harvey P. Dale_, Aug 09 2012 *)
%t CoefficientList[Series[(1 + 4*x^2)/(1 - x - x^3), {x, 0, 50}], x] (* _G. C. Greubel_, May 01 2017 *)
%o (PARI) x='x+O('x^50); Vec((1+4*x^2)/(1-x-x^3)) \\ _G. C. Greubel_, May 01 2017; corrected by _Georg Fischer_, May 18 2019
%Y Cf. A000930.
%K nonn
%O 0,3
%A Juan-Carlos Lerman (jclerm(AT)aztec.asu.edu)
%E Name corrected by _Arkadiusz Wesolowski_, Dec 05 2011
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