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.

A322110 Number of non-isomorphic connected multiset partitions of weight n that cannot be capped by a tree.

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%I A322110 #16 Feb 07 2021 19:42:27
%S A322110 1,1,3,6,15,32,86,216,628,1836,5822
%N A322110 Number of non-isomorphic connected multiset partitions of weight n that cannot be capped by a tree.
%C A322110 The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
%C A322110 The density of a multiset partition is defined to be the sum of numbers of distinct elements in each part, minus the number of parts, minus the total number of distinct elements in the whole partition. A multiset partition is a tree if it has more than one part, is connected, and has density -1. A cap is a certain kind of non-transitive coarsening of a multiset partition. For example, the four caps of {{1,1},{1,2},{2,2}} are {{1,1},{1,2},{2,2}}, {{1,1},{1,2,2}}, {{1,1,2},{2,2}}, {{1,1,2,2}}. - _Gus Wiseman_, Feb 05 2021
%H A322110 Gus Wiseman, <a href="http://www.mathematica-journal.com/2017/12/every-clutter-is-a-tree-of-blobs/">Every Clutter Is a Tree of Blobs</a>, The Mathematica Journal, Vol. 19, 2017.
%e A322110 The multiset partition C = {{1,1},{1,2,3},{2,3,3}} is not a tree but has the cap {{1,1},{1,2,3,3}} which is a tree, so C is not counted under a(8).
%e A322110 Non-isomorphic representatives of the a(1) = 1 through a(5) = 32 multiset partitions:
%e A322110   {{1}}  {{1,1}}    {{1,1,1}}      {{1,1,1,1}}        {{1,1,1,1,1}}
%e A322110          {{1,2}}    {{1,2,2}}      {{1,1,2,2}}        {{1,1,2,2,2}}
%e A322110          {{1},{1}}  {{1,2,3}}      {{1,2,2,2}}        {{1,2,2,2,2}}
%e A322110                     {{1},{1,1}}    {{1,2,3,3}}        {{1,2,2,3,3}}
%e A322110                     {{2},{1,2}}    {{1,2,3,4}}        {{1,2,3,3,3}}
%e A322110                     {{1},{1},{1}}  {{1},{1,1,1}}      {{1,2,3,4,4}}
%e A322110                                    {{1,1},{1,1}}      {{1,2,3,4,5}}
%e A322110                                    {{1},{1,2,2}}      {{1},{1,1,1,1}}
%e A322110                                    {{1,2},{1,2}}      {{1,1},{1,1,1}}
%e A322110                                    {{2},{1,2,2}}      {{1},{1,2,2,2}}
%e A322110                                    {{3},{1,2,3}}      {{1,2},{1,2,2}}
%e A322110                                    {{1},{1},{1,1}}    {{2},{1,1,2,2}}
%e A322110                                    {{1},{2},{1,2}}    {{2},{1,2,2,2}}
%e A322110                                    {{2},{2},{1,2}}    {{2},{1,2,3,3}}
%e A322110                                    {{1},{1},{1},{1}}  {{2,2},{1,2,2}}
%e A322110                                                       {{2,3},{1,2,3}}
%e A322110                                                       {{3},{1,2,3,3}}
%e A322110                                                       {{4},{1,2,3,4}}
%e A322110                                                       {{1},{1},{1,1,1}}
%e A322110                                                       {{1},{1,1},{1,1}}
%e A322110                                                       {{1},{1},{1,2,2}}
%e A322110                                                       {{1},{2},{1,2,2}}
%e A322110                                                       {{2},{1,2},{1,2}}
%e A322110                                                       {{2},{1,2},{2,2}}
%e A322110                                                       {{2},{2},{1,2,2}}
%e A322110                                                       {{2},{3},{1,2,3}}
%e A322110                                                       {{3},{1,3},{2,3}}
%e A322110                                                       {{3},{3},{1,2,3}}
%e A322110                                                       {{1},{1},{1},{1,1}}
%e A322110                                                       {{1},{2},{2},{1,2}}
%e A322110                                                       {{2},{2},{2},{1,2}}
%e A322110                                                       {{1},{1},{1},{1},{1}}
%Y A322110 Non-isomorphic tree multiset partitions are counted by A321229.
%Y A322110 The weak-antichain case is counted by A322117.
%Y A322110 The case without singletons is counted by A322118.
%Y A322110 Cf. A002218, A007718, A013922, A030019, A056156, A275307, A304118, A304382, A304887, A305052, A305079, A321194.
%K A322110 nonn,more
%O A322110 0,3
%A A322110 _Gus Wiseman_, Nov 26 2018
%E A322110 Corrected by _Gus Wiseman_, Jan 27 2021