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Number of non-isomorphic balanced reduced multisystems of weight n whose leaves (which are multisets of atoms) are all sets.
6

%I #8 Apr 27 2020 09:43:41

%S 1,1,1,3,22,204,2953

%N Number of non-isomorphic balanced reduced multisystems of weight n whose leaves (which are multisets of atoms) are all sets.

%C A balanced reduced multisystem is either a finite multiset, or a multiset partition with at least two parts, not all of which are singletons, of a balanced reduced multisystem. The weight of an atom is 1, while the weight of a multiset is the sum of weights of its elements.

%e Non-isomorphic representatives of the a(1) = 1 through a(4) = 22 multisystems:

%e {1} {1,2} {1,2,3} {1,2,3,4}

%e {{1},{1,2}} {{1},{1,2,3}}

%e {{1},{2,3}} {{1,2},{1,2}}

%e {{1,2},{1,3}}

%e {{1},{2,3,4}}

%e {{1,2},{3,4}}

%e {{1},{1},{1,2}}

%e {{1},{1},{2,3}}

%e {{1},{2},{1,2}}

%e {{1},{2},{1,3}}

%e {{1},{2},{3,4}}

%e {{{1}},{{1},{1,2}}}

%e {{{1}},{{1},{2,3}}}

%e {{{1,2}},{{1},{1}}}

%e {{{1}},{{2},{1,2}}}

%e {{{1,2}},{{1},{2}}}

%e {{{1}},{{2},{1,3}}}

%e {{{1,2}},{{1},{3}}}

%e {{{1}},{{2},{3,4}}}

%e {{{1,2}},{{3},{4}}}

%e {{{2}},{{1},{1,3}}}

%e {{{2,3}},{{1},{1}}}

%Y The case with all atoms different is A318813.

%Y The version where the leaves are multisets is A330474.

%Y The tree version is A330626.

%Y The maximum-depth case is A330677.

%Y Unlabeled series-reduced rooted trees whose leaves are sets are A330624.

%Y Cf. A000311, A004114, A005121, A005804, A007716, A048816, A141268, A283877, A306186, A318812, A320154, A330470, A330628, A330663.

%K nonn,more

%O 0,4

%A _Gus Wiseman_, Dec 27 2019