%I #8 Dec 31 2023 16:32:13
%S 1,1,1,6,16,31,76,201,481,1141,2806,6876,16651,40456,98641,240081,
%T 583801,1420726,3458056,8414391,20474356,49824601,121246801,295040781,
%U 717957766,1747108756,4251463651,10345607376,25175294881,61262300641
%N Expansion of (1+x)/((1-x)^2-5x^3).
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1,5).
%F G.f. : (1+x)/(1-2x+x^2-5x^3); a(n)=2a(n-1)-a(n-2)+5a(n-3); a(n)=sum{k=0..floor(n/2), binomial(n-k, 2k)5^k }.
%K easy,nonn
%O 0,4
%A _Paul Barry_, Jul 25 2004