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A052603
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E.g.f. (1-x)^3/(1-4x+3x^2-x^3).
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0
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1, 1, 8, 78, 984, 15480, 292320, 6441120, 162207360, 4595512320, 144662112000, 5009199148800, 189221439052800, 7743449813299200, 341258374762905600, 16113703632009984000, 811588993992032256000, 43431603596770701312000
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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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E.g.f.: (-1+x)^3/(-1+4*x-3*x^2+x^3)
Recurrence: {a(1)=1, a(0)=1, a(2)=8, (-11*n-6-n^3-6*n^2)*a(n)+(18+3*n^2+15*n)*a(n+1)+(-4*n-12)*a(n+2)+a(n+3)=0, a(3)=78}
Sum(-1/31*(5*_alpha+3*_alpha^2-6)*_alpha^(-1-n), _alpha=RootOf(-1+4*_Z-3*_Z^2+_Z^3))*n!
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MAPLE
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spec := [S, {S=Sequence(Prod(Z, Sequence(Z), Sequence(Z), Sequence(Z)))}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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encyclopedia(AT)pommard.inria.fr, Jan 25 2000
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STATUS
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approved
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