|
|
A319721
|
|
Number of non-isomorphic antichains of multisets of weight n.
|
|
35
|
|
|
1, 1, 4, 8, 24, 50, 148, 349, 1014, 2717, 8114
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
COMMENTS
|
In an antichain, no part is a proper submultiset of any other. The weight of an antichain is the sum of sizes of its parts. Weight is generally not the same as number of vertices.
|
|
LINKS
|
|
|
EXAMPLE
|
Non-isomorphic representatives of the a(1) = 1 through a(3) = 8 antichains:
1: {{1}}
2: {{1,1}}
{{1,2}}
{{1},{1}}
{{1},{2}}
3: {{1,1,1}}
{{1,2,2}}
{{1,2,3}}
{{1},{2,2}}
{{1},{2,3}}
{{1},{1},{1}}
{{1},{2},{2}}
{{1},{2},{3}}
|
|
CROSSREFS
|
Cf. A001055, A001970, A007716, A096827, A253249, A285572, A285573, A293993, A318099, A319616-A319646, A319719.
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|