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A052574
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E.g.f. (1-2x)/(1-3x+x^2).
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0
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1, 1, 4, 30, 312, 4080, 64080, 1174320, 24595200, 579519360, 15172012800, 436929292800, 13726748851200, 467182235520000, 17123385600921600, 672444082582272000, 28167703419727872000, 1253648083943743488000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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LINKS
| INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 517
Vladimir Kruchinin, Compositae and their properties, arXiv:1103.2582
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FORMULA
| E.g.f.: -(-1+2*x)/(1-3*x+x^2)
Recurrence: {a(1)=1, a(0)=1, (n^2+3*n+2)*a(n)+(-6-3*n)*a(n+1)+a(n+2)=0}
Sum(1/5*(-1+4*_alpha)*_alpha^(-1-n), _alpha=RootOf(_Z^2-3*_Z+1))*n!
a(n)=n!*sum(binomial(n-1,k-1)*Fibonacci(k),k,1,n); n>0 [From Kruchinin Vladimir (kru(AT)ie.tusur.ru), Sep 01 2010]
a(n) = n!*A001519(n). - R. J. Mathar, Mov 27 2011
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MAPLE
| spec := [S, {S=Sequence(Prod(Z, Sequence(Prod(Z, Sequence(Z)))))}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
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CROSSREFS
| Sequence in context: A052452 A088794 A145348 * A158834 A139086 A180623
Adjacent sequences: A052571 A052572 A052573 * A052575 A052576 A052577
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KEYWORD
| easy,nonn
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AUTHOR
| encyclopedia(AT)pommard.inria.fr, Jan 25 2000
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