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A178171
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Number of collections of nonempty subsets of an n-element set where each element appears in at most 3 subsets.
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4
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1, 2, 8, 109, 3623, 200522, 16514461, 1912959395, 298569495981, 60701549078701, 15647889334180500, 5003666238486522124, 1948975409748003520112, 910680909359710587298621, 503845222094502583681150340, 326363222435413478204610417626, 245078255691857705139839897934085
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OFFSET
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0,2
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LINKS
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CROSSREFS
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At most 1 subset gives Bell numbers A000110, at most 2 subsets gives A178165.
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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