Displaying 1-10 of 16 results found.
Number of non-isomorphic connected strict multiset partitions (sets of multisets) of weight n with empty intersection.
+0
1
1, 0, 0, 0, 1, 4, 24, 96, 412, 1607, 6348, 24580, 96334, 378569, 1508220, 6079720, 24879878, 103335386, 436032901, 1869019800, 8139613977, 36008825317, 161794412893, 738167013847, 3418757243139, 16068569129711, 76622168743677, 370571105669576, 1817199912384794
COMMENTS
The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
EXAMPLE
Non-isomorphic representatives of the a(4) = 1 through a(5) = 4 multiset partitions:
4: {{1},{2},{1,2}}
5: {{1},{2},{1,2,2}}
{{1},{1,2},{2,2}}
{{2},{3},{1,2,3}}
{{2},{1,3},{2,3}}
Number of non-isomorphic connected set systems of weight n with empty intersection.
+0
1
1, 0, 0, 0, 1, 2, 9, 22, 69, 190, 567, 1640, 5025, 15404, 49048, 159074, 531165, 1813627, 6352739, 22759620, 83443086, 312612543, 1196356133, 4672620842, 18615188819, 75593464871, 312729620542, 1317267618429, 5646454341658, 24618309943464, 109123789229297
COMMENTS
The weight of a set system is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
EXAMPLE
Non-isomorphic representatives of the a(4) = 1 through a(6) = 9 connected set systems:
4: {{1},{2},{1,2}}
5: {{2},{3},{1,2,3}}
{{2},{1,3},{2,3}}
6: {{1},{1,4},{2,3,4}}
{{1},{2,3},{1,2,3}}
{{3},{4},{1,2,3,4}}
{{3},{1,4},{2,3,4}}
{{1,2},{1,3},{2,3}}
{{1,3},{2,4},{3,4}}
{{1},{2},{3},{1,2,3}}
{{1},{2},{1,3},{2,3}}
{{2},{3},{1,3},{2,3}}
CROSSREFS
Cf. A007716, A007718, A049311, A056156, A281116, A283877, A300913, A305854, A316980, A317752, A317755, A317757.
Number of non-isomorphic connected set multipartitions (multisets of sets) of weight n with empty intersection.
+0
5
1, 0, 0, 0, 1, 3, 14, 38, 125, 360, 1107, 3297, 10292, 32134, 103759, 340566, 1148150, 3951339, 13925330, 50122316, 184365292, 692145409, 2651444318, 10356184440, 41224744182, 167150406897, 689998967755, 2898493498253, 12384852601731, 53804601888559, 237566072006014
COMMENTS
The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
EXAMPLE
Non-isomorphic representatives of the a(4) = 1 through a(6) = 14 set multipartitions:
4: {{1},{2},{1,2}}
5: {{2},{3},{1,2,3}}
{{2},{1,3},{2,3}}
{{1},{2},{2},{1,2}}
6: {{1},{1,4},{2,3,4}}
{{1},{2,3},{1,2,3}}
{{3},{4},{1,2,3,4}}
{{3},{1,4},{2,3,4}}
{{1,2},{1,3},{2,3}}
{{1,3},{2,4},{3,4}}
{{1},{2},{3},{1,2,3}}
{{1},{2},{1,2},{1,2}}
{{1},{2},{1,3},{2,3}}
{{2},{2},{1,3},{2,3}}
{{2},{3},{3},{1,2,3}}
{{2},{3},{1,3},{2,3}}
{{1},{1},{2},{2},{1,2}}
{{1},{2},{2},{2},{1,2}}
Number of non-isomorphic connected multiset partitions of weight n with empty intersection.
+0
5
1, 0, 0, 0, 1, 5, 32, 134, 588, 2335, 9335, 36506, 144263, 571238, 2291894, 9300462, 38303796, 160062325, 679333926, 2927951665, 12817221628, 56974693933, 257132512297, 1177882648846, 5475237760563, 25818721638720, 123473772356785, 598687942799298, 2942344764127039
COMMENTS
The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
EXAMPLE
Non-isomorphic representatives of the a(4) = 1 through a(5) = 5 connected multiset partitions:
4: {{1},{2},{1,2}}
5: {{1},{2},{1,2,2}}
{{1},{1,2},{2,2}}
{{2},{3},{1,2,3}}
{{2},{1,3},{2,3}}
{{1},{2},{2},{1,2}}
Number of set systems spanning n vertices with empty intersection whose dual is also a set system with empty intersection.
+0
4
COMMENTS
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}}.
EXAMPLE
The a(3) = 1 set system is {{1,2},{1,3},{2,3}}.
Number of intersecting multiset partitions of weight n whose dual is not an intersecting multiset partition.
+0
16
1, 0, 0, 0, 1, 4, 20, 66, 226, 696, 2156
COMMENTS
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}}.
The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
A multiset partition is intersecting iff no two parts are disjoint. The dual of a multiset partition is intersecting iff every pair of distinct vertices appear together in some part.
EXAMPLE
Non-isomorphic representatives of the a(4) = 1 through a(6) = 20 multiset partitions:
4: {{1,3},{2,3}}
5: {{1,2},{2,3,3}}
{{1,3},{2,3,3}}
{{1,4},{2,3,4}}
{{3},{1,3},{2,3}}
6: {{1,2},{2,3,3,3}}
{{1,3},{2,2,3,3}}
{{1,3},{2,3,3,3}}
{{1,3},{2,3,4,4}}
{{1,4},{2,3,4,4}}
{{1,5},{2,3,4,5}}
{{1,1,2},{2,3,3}}
{{1,2,2},{2,3,3}}
{{1,2,3},{3,4,4}}
{{1,2,4},{3,4,4}}
{{1,2,5},{3,4,5}}
{{1,3,3},{2,3,3}}
{{1,3,4},{2,3,4}}
{{2},{1,2},{2,3,3}}
{{3},{1,3},{2,3,3}}
{{4},{1,4},{2,3,4}}
{{1,3},{2,3},{2,3}}
{{1,3},{2,3},{3,3}}
{{1,4},{2,4},{3,4}}
{{3},{3},{1,3},{2,3}}
Number of non-isomorphic set systems of weight n with empty intersection whose dual is also a set system with empty intersection.
+0
12
1, 0, 1, 1, 2, 5, 13, 28, 72, 181, 483
COMMENTS
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}}. The dual of a multiset partition has empty intersection iff no part contains all the vertices.
The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
EXAMPLE
Non-isomorphic representatives of the a(2) = 1 through a(6) = 13 multiset partitions:
2: {{1},{2}}
3: {{1},{2},{3}}
4: {{1},{3},{2,3}}
{{1},{2},{3},{4}}
5: {{1},{2,4},{3,4}}
{{2},{1,3},{2,3}}
{{1},{2},{3},{2,3}}
{{1},{2},{4},{3,4}}
{{1},{2},{3},{4},{5}}
6: {{3},{1,4},{2,3,4}}
{{1,2},{1,3},{2,3}}
{{1,3},{2,4},{3,4}}
{{1},{2},{1,3},{2,3}}
{{1},{2},{3,5},{4,5}}
{{1},{3},{4},{2,3,4}}
{{1},{3},{2,4},{3,4}}
{{1},{4},{2,4},{3,4}}
{{2},{3},{1,3},{2,3}}
{{2},{4},{1,2},{3,4}}
{{1},{2},{3},{4},{3,4}}
{{1},{2},{3},{5},{4,5}}
{{1},{2},{3},{4},{5},{6}}
Number of non-isomorphic multiset partitions of weight n with empty intersection and no part containing all the vertices.
+0
4
1, 0, 1, 4, 16, 52, 185, 625, 2226, 7840, 28405
COMMENTS
The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
EXAMPLE
Non-isomorphic representatives of the a(2) = 1 through a(4) = 16 multiset partitions:
2: {{1},{2}}
3: {{1},{2,2}}
{{1},{2,3}}
{{1},{2},{2}}
{{1},{2},{3}}
4: {{1},{2,2,2}}
{{1},{2,3,3}}
{{1},{2,3,4}}
{{1,1},{2,2}}
{{1,2},{3,3}}
{{1,2},{3,4}}
{{1},{1},{2,2}}
{{1},{1},{2,3}}
{{1},{2},{2,2}}
{{1},{2},{3,3}}
{{1},{2},{3,4}}
{{1},{3},{2,3}}
{{1},{1},{2},{2}}
{{1},{2},{2},{2}}
{{1},{2},{3},{3}}
{{1},{2},{3},{4}}
Number of non-isomorphic intersecting set systems of weight n with empty intersection.
+0
4
1, 0, 0, 0, 0, 0, 1, 1, 3, 8, 18
COMMENTS
A set system is a finite set of finite nonempty sets. It is intersecting if no two parts are disjoint. The weight of a set system is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
EXAMPLE
Non-isomorphic representatives of the a(6) = 1 through a(9) = 8 set systems:
6: {{1,2},{1,3},{2,3}}
7: {{1,3},{1,4},{2,3,4}}
8: {{1,2},{1,3,4},{2,3,4}}
{{1,4},{1,5},{2,3,4,5}}
{{2,4},{1,2,5},{3,4,5}}
9: {{1,3},{1,4,5},{2,3,4,5}}
{{1,5},{1,6},{2,3,4,5,6}}
{{2,5},{1,2,6},{3,4,5,6}}
{{1,2,3},{2,4,5},{3,4,5}}
{{1,3,5},{2,3,6},{4,5,6}}
{{1,2},{1,3},{1,4},{2,3,4}}
{{1,2},{1,3},{2,3},{1,2,3}}
{{1,3},{1,4},{3,4},{2,3,4}}
CROSSREFS
Cf. A007716, A281116, A283877, A305854, A306006, A316980, A317752, A317755, A317757, A318715, A318717.
Number of non-isomorphic strict intersecting multiset partitions (sets of multisets) of weight n with empty intersection.
+0
4
1, 0, 0, 0, 0, 0, 1, 2, 12, 46, 181
COMMENTS
A multiset partition is intersecting if no two parts are disjoint. The weight of a multiset partition is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
EXAMPLE
Non-isomorphic representatives of the a(6) = 1 through a(8) = 12 multiset partitions:
6: {{1,2},{1,3},{2,3}}
7: {{1,2},{1,3},{2,3,3}}
{{1,3},{1,4},{2,3,4}}
8: {{1,2},{1,3},{2,2,3,3}}
{{1,2},{1,3},{2,3,3,3}}
{{1,2},{1,3},{2,3,4,4}}
{{1,2},{1,3,3},{2,3,3}}
{{1,2},{1,3,4},{2,3,4}}
{{1,3},{1,4},{2,3,4,4}}
{{1,3},{1,1,2},{2,3,3}}
{{1,3},{1,2,2},{2,3,3}}
{{1,4},{1,5},{2,3,4,5}}
{{2,3},{1,2,4},{3,4,4}}
{{2,4},{1,2,3},{3,4,4}}
{{2,4},{1,2,5},{3,4,5}}
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