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%I #6 Jun 13 2015 00:51:50
%S 1,2,5,12,30,76,194,496,1267,3230,8215,20844,52768,133304,336100,
%T 845888,2125381,5332058,13357833,33419820,83510018,208437060,
%U 519691110,1294430448,3221081335,8008262966,19893476315,49378623564,122473408452
%N Expansion of (1-2x)^2/((1-x)^2(1-2x-x^2)^2).
%C Row sums of number triangle A108359.
%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (6,-11,4,5,-2,-1).
%F G.f.: (1-4x+4x^2)/(1-6x+11x^2-4x^3-5x^4+2x^5+x^6); a(n)=sum{k=0..n, sum{j=0..n-k, C(k, j)C(n-j, k)*floor((j+2)/2)}}.
%K easy,nonn
%O 0,2
%A _Paul Barry_, May 31 2005
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