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Expansion of (1+x)/((1-x)^2-5x^3).
0

%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