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a(n)=Sum{T(2i,n-2i): i=0,1,...,[ n/2 ]}, array T as in A049600.
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%I #11 Oct 26 2015 07:47:42

%S 0,0,2,3,12,25,76,182,504,1275,3410,8811,23256,60580,159094,415715,

%T 1089648,2850645,7466468,19541994,51170460,133951675,350713222,

%U 918141623,2403786672,6293097000,16475700746,43133687427,112925875764

%N a(n)=Sum{T(2i,n-2i): i=0,1,...,[ n/2 ]}, array T as in A049600.

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (2,3,-4,1).

%F G.f.: x^2*(-2+x) / ( (x^2-x-1)*(x^2-3*x+1) ).

%F a(n) = (Fibonacci(2*n)+(-1)^n*Fibonacci(n))/2. - _Vladeta Jovovic_, Aug 30 2004

%Y Cf. A049602.

%K nonn,easy

%O 0,3

%A _Clark Kimberling_