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A320807 Number of non-isomorphic multiset partitions of weight n in which all parts are aperiodic and all parts of the dual are also aperiodic. 1

%I #4 Nov 07 2018 21:45:53

%S 1,1,3,6,17,41,122,345,1077,3385,11214

%N Number of non-isomorphic multiset partitions of weight n in which all parts are aperiodic and all parts of the dual are also aperiodic.

%C Also the number of nonnegative integer matrices up to row and column permutations with sum of entries equal to n and no zero rows or columns, in which each row and each column has relatively prime nonzero entries.

%C The dual of a multiset partition has, for each vertex, one part consisting of the indices (or positions) of the parts containing that vertex, counted with multiplicity. For example, the dual of {{1,2},{2,2}} is {{1},{1,2,2}}.

%C A multiset is aperiodic if its multiplicities are relatively prime.

%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(1) = 1 through a(4) = 17 multiset partitions:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

%Y Cf. A000740, A000837, A007716, A007916, A100953, A301700, A303386, A303546, A303707, A303708, A316983, A320800-A320810.

%K nonn,more

%O 0,3

%A _Gus Wiseman_, Nov 07 2018

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Last modified April 16 17:08 EDT 2024. Contains 371749 sequences. (Running on oeis4.)