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Number of non-isomorphic weight-n blobs (2-connected weak antichains) of multisets with no singletons.
3

%I #4 Nov 28 2018 08:03:18

%S 1,0,2,3,7,7,20,26,78,184,553

%N Number of non-isomorphic weight-n blobs (2-connected weak antichains) of multisets with no singletons.

%C The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.

%e Non-isomorphic representatives of the a(2) = 2 through a(7) = 26 blobs:

%e {{11}} {{111}} {{1111}} {{11111}} {{111111}} {{1111111}}

%e {{12}} {{122}} {{1122}} {{11222}} {{111222}} {{1112222}}

%e {{123}} {{1222}} {{12222}} {{112222}} {{1122222}}

%e {{1233}} {{12233}} {{112233}} {{1122333}}

%e {{1234}} {{12333}} {{122222}} {{1222222}}

%e {{11}{11}} {{12344}} {{122333}} {{1222333}}

%e {{12}{12}} {{12345}} {{123333}} {{1223333}}

%e {{123344}} {{1223344}}

%e {{123444}} {{1233333}}

%e {{123455}} {{1233444}}

%e {{123456}} {{1234444}}

%e {{111}{111}} {{1234455}}

%e {{112}{122}} {{1234555}}

%e {{122}{122}} {{1234566}}

%e {{123}{123}} {{1234567}}

%e {{123}{233}} {{112}{1222}}

%e {{134}{234}} {{122}{1233}}

%e {{11}{11}{11}} {{123}{2233}}

%e {{12}{12}{12}} {{123}{2333}}

%e {{12}{13}{23}} {{123}{2344}}

%e {{134}{2344}}

%e {{145}{2345}}

%e {{223}{1233}}

%e {{344}{1234}}

%e {{12}{13}{233}}

%e {{13}{14}{234}}

%Y Cf. A002218, A007718, A013922, A275307, A286520, A293994, A304118, A304887, A319719, A322110, A322117, A322118.

%K nonn,more

%O 0,3

%A _Gus Wiseman_, Nov 27 2018