cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A320805 Number of non-isomorphic multiset partitions of weight n in which each part, as well as the multiset union of the parts, is an aperiodic multiset.

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%I A320805 #5 Nov 07 2018 21:45:25
%S A320805 1,1,2,6,16,55,139,516,1500,5269,17017
%N A320805 Number of non-isomorphic multiset partitions of weight n in which each part, as well as the multiset union of the parts, is an aperiodic multiset.
%C A320805 Also the number of nonnegative integer matrices up to row and column permutations with sum of elements equal to n and no zero rows or columns, in which (1) the positive entries in each row are relatively prime and (2) the column sums are relatively prime.
%C A320805 A multiset is aperiodic if its multiplicities are relatively prime.
%C A320805 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 A320805 Non-isomorphic representatives of the a(1) = 1 through a(4) = 16 multiset partitions:
%e A320805   {{1}}  {{1,2}}    {{1,2,2}}      {{1,2,2,2}}
%e A320805          {{1},{2}}  {{1,2,3}}      {{1,2,3,3}}
%e A320805                     {{1},{2,3}}    {{1,2,3,4}}
%e A320805                     {{2},{1,2}}    {{1},{2,3,3}}
%e A320805                     {{1},{2},{2}}  {{1},{2,3,4}}
%e A320805                     {{1},{2},{3}}  {{1,2},{3,4}}
%e A320805                                    {{1,3},{2,3}}
%e A320805                                    {{2},{1,2,2}}
%e A320805                                    {{3},{1,2,3}}
%e A320805                                    {{1},{1},{2,3}}
%e A320805                                    {{1},{2},{3,4}}
%e A320805                                    {{1},{3},{2,3}}
%e A320805                                    {{2},{2},{1,2}}
%e A320805                                    {{1},{2},{2},{2}}
%e A320805                                    {{1},{2},{3},{3}}
%e A320805                                    {{1},{2},{3},{4}}
%Y A320805 Cf. A000740, A000837, A007716, A007916, A100953, A301700, A303386, A303546, A303707, A303708, A303710, A320800-A320810, A321283.
%K A320805 nonn,more
%O A320805 0,3
%A A320805 _Gus Wiseman_, Nov 07 2018