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A243633
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Expansion of (4*x^3-6*x^2+4*x-1)/(5*x^3-8*x^2+5*x-1).
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0
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1, 1, 3, 8, 21, 56, 152, 417, 1149, 3169, 8738, 24083, 66356, 182806, 503597, 1387317, 3821839, 10528644, 29005093, 79905508, 220130016, 606431481, 1670644817, 4602422317, 12679110454, 34929397819, 96226217048, 265091454958
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OFFSET
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0,3
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LINKS
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FORMULA
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a(n) = sum(m=0..n, sum(k=0..n/2, binomial(m+k-1,k)*binomial(n+m-1,n-4*k-m))).
A(x) = 1/(1-F(x)), where F(x) is g.f. A038504.
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PROG
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(Maxima)
a(n):=sum(sum(binomial(m+k-1, k)*binomial(n+m-1, n-4*k-m), k, 0, n/2), m, 0, n);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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