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

%I #6 Jun 13 2015 00:51:54

%S 0,1,4,11,25,52,102,193,356,645,1153,2040,3580,6241,10820,18671,32089,

%T 54956,93826,159745,271300,459721,777409,1312176,2211000,3719617,

%U 6248452,10482323,17562841,29391460,49132638,82048705,136884260

%N Expansion of x(1-x^2-x^3)/((1-x)(1-x-x^2))^2.

%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (4,-4,-2,4,0,-1)

%F a(n)=4a(n-1)-4a(n-2)-2a(n-3)+4a(n-4)-a(n-6); a(n)=sum{k=0..n, (n-k)*C(n-k, k+1)}; a(n)=n*(F(n+2)-1)-(1+((n-5)*F(n-1)+(3n-8)*F(n))/5).

%Y Cf. A045925, A006478, A023610.

%K easy,nonn

%O 0,3

%A _Paul Barry_, Nov 05 2005