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A180958 Diagonal sums of generalized Narayana triangle A180957. 1

%I

%S 1,1,2,2,2,-1,-8,-25,-57,-114,-202,-322,-447,-496,-271,625,2914,7762,

%T 16834,32063,54760,83319,108375,103726,11110,-282498,-973439,-2366432,

%U -4869919,-8903455,-14604094

%N Diagonal sums of generalized Narayana triangle A180957.

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

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

%F a(n)=sum{k=0..floor(n/2), sum{j=0..n-k, C(n-k,j)*C(n-k-j,2(k-j)*(-1)^(k-j)}}.

%K easy,sign

%O 0,3

%A _Paul Barry_, Sep 28 2010

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Last modified September 20 01:58 EDT 2019. Contains 327207 sequences. (Running on oeis4.)