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A326868型
n个顶点上的连通连通系统数。
8
1, 1, 4, 64, 6048, 8064000, 1196002238976
抵消
0,3
评论
我们将连通系统(由Vim van Dam于2002年研究)定义为一组有限的非空集(边),在取任意两条重叠边的并集的情况下是闭合的。如果它为空或包含带有所有顶点的边,则它是连接的。
链接
古斯·怀斯曼,每一个斑点都是一棵斑点树《数学杂志》,2017年第19卷。
配方奶粉
a(n>1)=2^n*A072447号(n) ●●●●。
的对数变换A326870型.
例子
a(3)=64连通连通系统:
{{123}} {{1}{123}}
{{12}{123}} {{2}{123}}
{{13}{123}} {{3}{123}}
{{23}{123}} {{1}{12}{123}}
{{12}{13}{123}} {{1}{13}{123}}
{{12}{23}{123}} {{1}{23}{123}}
{{13}{23}{123}} {{2}{12}{123}}
{{12}{13}{23}{123}} {{2}{13}{123}}
{{2}{23}{123}}
{{3}{12}{123}}
{{3}{13}{123}}
{{3}{23}{123}}
{{1}{12}{13}{123}}
{{1}{12}{23}{123}}
{{1}{13}{23}{123}}
{{2}{12}{13}{123}}
{{2}{12}{23}{123}}
{{2}{13}{23}{123}}
{{3}{12}{13}{123}}
{{3}{12}{23}{123}}
{{3}{13}{23}{123}}
{{1}{12}{13}{23}{123}}
{{2}{12}{13}{23}{123}}
{{3}{12}{13}{23}{123}}
.
{{1}{2}{123}} {{1}{2}{3}{123}}
{{1}{3}{123}} {{1}{2}{3}{12}{123}}
{{2}{3}{123}} {{1}{2}{3}{13}{123}}
{{1}{2}{12}{123}} {{1}{2}{3}{23}{123}}
{{1}{2}{13}{123}} {{1}{2}{3}{12}{13}{123}}
{{1}{2}{23}{123}} {{1}{2}{3}{12}{23}{123}}
{{1}{3}{12}{123}} {{1}{2}{3}{13}{23}{123}}
{{1}{3}{13}{123}} {{1}{2}{3}{12}{13}{23}{123}}
{{1}{3}{23}{123}}
{{2}{3}{12}{123}}
{{2}{3}{13}{123}}
{{2}{3}{23}{123}}
{{1}{2}{12}{13}{123}}
{{1}{2}{12}{23}{123}}
{{1}{2}{13}{23}{123}}
{{1}{3}{12}{13}{123}}
{{1}{3}{12}{23}{123}}
{{1}{3}{13}{23}{123}}
{{2}{3}{12}{13}{123}}
{{2}{3}{12}{23}{123}}
{{2}{3}{13}{23}{123}}
{{1}{2}{12}{13}{23}{123}}
{{1}{3}{12}{13}{23}{123}}
{{2}{3}{12}{13}{23}{123}}
数学
表[Length[Select[Subsets[Subsets[Range[n],{1,n}]],n==0||MemberQ[#,Range[n]]&&SubsetQ[#、Union@@@Select[Tuples[#,2],Intersection@@#={}&]]&]],{n,0,4}]
交叉参考
没有单例的情况是A072447号.
不一定连接的情况是A326866型.
未标记的案例是A326869型.
这些集合系统的BII编号为A326879型.
关键词
非n,更多
作者
古斯·怀斯曼2019年7月29日
扩展
a(6)修正人克里斯蒂安·西弗斯2023年10月28日
状态
经核准的