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A178171
Number of collections of nonempty subsets of an n-element set where each element appears in at most 3 subsets.
4
1, 2, 8, 109, 3623, 200522, 16514461, 1912959395, 298569495981, 60701549078701, 15647889334180500, 5003666238486522124, 1948975409748003520112, 910680909359710587298621, 503845222094502583681150340, 326363222435413478204610417626, 245078255691857705139839897934085
OFFSET
0,2
LINKS
CROSSREFS
Row n=3 of A330964.
At most 1 subset gives Bell numbers A000110, at most 2 subsets gives A178165.
Sequence in context: A136468 A374875 A322643 * A374573 A132523 A012554
KEYWORD
nonn
AUTHOR
Daniel E. Loeb, Dec 17 2010
EXTENSIONS
a(7)-a(8) from Bert Dobbelaere, Sep 10 2019
Terms a(9) and beyond from Andrew Howroyd, Jan 04 2020
STATUS
approved