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A052629
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E.g.f. (1-x)/(1-5x+3x^2).
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0
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1, 4, 34, 438, 7536, 162120, 4185360, 126060480, 4339278720, 168038478720, 7230318681600, 342214829510400, 17669683572710400, 988372892015308800, 59538455210371737600, 3842709218808235776000, 264549049753191211008000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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LINKS
| INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 575
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FORMULA
| E.g.f.: -(-1+x)/(1-5*x+3*x^2)
Recurrence: {a(0)=1, a(1)=4, (3*n^2+9*n+6)*a(n) +(-10-5*n)*a(n+1) +a(n+2)=0}
Sum(-1/13*(-3+_alpha)*_alpha^(-1-n), _alpha=RootOf(1-5*_Z+3*_Z^2))*n!
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MAPLE
| spec := [S, {S=Sequence(Union(Z, Z, Z, Prod(Z, Sequence(Z))))}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
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CROSSREFS
| Sequence in context: A145349 A052630 A071213 * A151919 A193099 A198976
Adjacent sequences: A052626 A052627 A052628 * A052630 A052631 A052632
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KEYWORD
| easy,nonn
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AUTHOR
| encyclopedia(AT)pommard.inria.fr, Jan 25 2000
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