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A052877
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A simple grammar.
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0
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0, 2, 3, 7, 27, 151, 1083, 9367, 94587, 1091671, 14174523, 204495127, 3245265147, 56183135191, 1053716696763, 21282685940887, 460566381955707, 10631309363962711, 260741534058271803, 6771069326513690647
(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 848
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FORMULA
| E.g.f.: exp(x)-1+ln(-1/(-2+exp(x)))
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MAPLE
| spec := [S, {B=Set(Z, 1 <= card), C=Cycle(B), S=Union(B, C)}, labeled]: seq(combstruct[count](spec, size=n), n=0..20);
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CROSSREFS
| a(n) = A000629(n-1)+1, n>0. Cf. A002050.
Sequence in context: A107881 A128001 A156142 * A137075 A060412 A062573
Adjacent sequences: A052874 A052875 A052876 * A052878 A052879 A052880
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KEYWORD
| easy,nonn
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AUTHOR
| encyclopedia(AT)pommard.inria.fr, Jan 25 2000
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