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A052814
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A simple grammar.
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0
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0, 1, 1, 2, 6, 16, 49, 156, 511, 1723, 5942, 20817, 73938, 265611, 963225, 3521667, 12966696, 48037862, 178936340, 669748197, 2517688316, 9501290664, 35982633397, 136708135198, 520914346328, 1990230295787, 7622765394301, 29262526895379, 112571409093256
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,4
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LINKS
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MAPLE
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spec := [S, {B=PowerSet(C), S=Prod(B, Z), C=Cycle(S)}, unlabeled]: 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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EXTENSIONS
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STATUS
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approved
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