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A047684
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Number of reduced contexts on n unlabeled objects.
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0
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OFFSET
| 1,2
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COMMENTS
| Equivalently, number of closure systems on n points, up to isomorphism.
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REFERENCES
| Bernhard Ganter, Rudolf Wille: Formal Concept Analysis, Springer-Verlag, 1999, ISBN 3-540-62771-5, p. 59.
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CROSSREFS
| Sequence in context: A067966 A165327 A090242 * A162955 A197314 A064448
Adjacent sequences: A047681 A047682 A047683 * A047685 A047686 A047687
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KEYWORD
| hard,nonn,nice
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AUTHOR
| Bernhard Ganter (ganter(AT)math.tu-dresden.de)
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