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A112518 Expansion of 1/(1-x+2x^3+x^4). 1

%I

%S 1,1,1,-1,-4,-7,-6,3,21,40,40,-5,-106,-226,-256,-39,519,1257,1591,592,

%T -2441,-6880,-9655,-5365,10836,37026,57411,41104,-43784,-195632,

%U -335251,-288787,146261,1012395,1925220,1921485,-249566,-5112401,-10880591,-12302944

%N Expansion of 1/(1-x+2x^3+x^4).

%C Row sums of A112517.

%F a(n)=a(n-1)-2a(n-3)-a(n-4); a(n)=sum{k=0..n, sum{j=0..n, C(j, n-j)C(k, j-k)(-1)^(j-k)}}.

%K easy,sign

%O 0,5

%A _Paul Barry_, Sep 09 2005

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Last modified June 24 00:14 EDT 2021. Contains 345403 sequences. (Running on oeis4.)