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A052767
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A simple grammar.
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1
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0, 0, 0, 0, 0, 120, 1800, 21000, 235200, 2693880, 32319000, 410031600, 5519487600, 78864820320, 1194924450720, 19166592681600, 324817601472000, 5803921108010880, 109115988701293440, 2154085473710580480
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OFFSET
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0,6
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LINKS
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Table of n, a(n) for n=0..19.
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 724
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FORMULA
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E.g.f.: ln(-1/(-1+x))^5
Recurrence: {a(1)=0, a(0)=0, a(2)=0, a(4)=0, a(3)=0, (-1-5*n-10*n^2-10*n^3-5*n^4-n^5)*a(n+1)+(31+5*n^4+70*n^2+30*n^3+75*n)*a(n+2)+(-125*n-90-60*n^2-10*n^3)*a(n+3)+(10*n^2+65+50*n)*a(n+4)+(-15-5*n)*a(n+5)+a(n+6), a(5)=120}
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MAPLE
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spec := [S, {B=Cycle(Z), S=Prod(B, B, B, B, B)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
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CROSSREFS
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Sequence in context: A053567 A056270 A001118 * A110839 A219720 A144858
Adjacent sequences: A052764 A052765 A052766 * A052768 A052769 A052770
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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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