

A319565


Number of nonisomorphic connected strict T_0 multiset partitions of weight n.


20



1, 1, 1, 4, 8, 21, 62, 175, 553, 1775, 6007
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OFFSET

0,4


COMMENTS

In a multiset partition, two vertices are equivalent if in every block the multiplicity of the first is equal to the multiplicity of the second. The T_0 condition means that there are no equivalent vertices.
The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.


LINKS

Table of n, a(n) for n=0..10.


EXAMPLE

Nonisomorphic representatives of the a(1) = 1 through a(4) = 8 multiset partitions:
1: {{1}}
2: {{1,1}}
3: {{1,1,1}}
{{1,2,2}}
{{1},{1,1}}
{{2},{1,2}}
4: {{1,1,1,1}}
{{1,2,2,2}}
{{1},{1,1,1}}
{{1},{1,2,2}}
{{2},{1,2,2}}
{{1,2},{2,2}}
{{1,3},{2,3}}
{{1},{2},{1,2}}


CROSSREFS

Cf. A007716, A007718, A049311, A056156, A059201, A283877, A316980.
Cf. A319557, A319558, A319559, A319560, A319564, A319566, A319567.
Sequence in context: A097076 A003608 A248423 * A129794 A064503 A050482
Adjacent sequences: A319562 A319563 A319564 * A319566 A319567 A319568


KEYWORD

nonn,more


AUTHOR

Gus Wiseman, Sep 23 2018


STATUS

approved



