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A323792
Number of non-isomorphic weight-n multisets of sets of sets.
9
1, 1, 4, 11, 43, 145, 614, 2549
OFFSET
0,3
COMMENTS
All sets and multisets must be finite, and only the outermost may be empty.
The weight of an atom is 1, and the weight of a multiset is the sum of weights of its elements, counting multiplicity.
EXAMPLE
Non-isomorphic representatives of the a(1) = 1 through a(3) = 11 multiset partitions:
{{1}} {{12}} {{123}}
{{1}{2}} {{1}{12}}
{{1}}{{1}} {{1}{23}}
{{1}}{{2}} {{1}}{{12}}
{{1}}{{23}}
{{1}{2}{3}}
{{1}}{{1}{2}}
{{1}}{{2}{3}}
{{1}}{{1}}{{1}}
{{1}}{{1}}{{2}}
{{1}}{{2}}{{3}}
KEYWORD
nonn,more
AUTHOR
Gus Wiseman, Jan 27 2019
STATUS
approved