A319789 Number of intersecting multiset partitions of strongly normal multisets of size n.

1, 1, 3, 6, 17, 40, 122, 330, 1032

Offset: 0

Author

Gus Wiseman, Sep 27 2018

Keywords

• nonn
• more

Comments

A multiset is normal if it spans an initial interval of positive integers, and strongly normal if in addition its multiplicities are weakly decreasing. A multiset partition is intersecting iff no two parts are disjoint.

Examples

			The a(1) = 1 through a(3) = 6 multiset partitions:
1: {{1}}
2: {{1,1}}
   {{1,2}}
   {{1},{1}}
3: {{1,1,1}}
   {{1,1,2}}
   {{1,2,3}}
   {{1},{1,1}}
   {{1},{1,2}}
   {{1},{1},{1}}
		

Crossrefs

Cf. A007716, A283877, A305854, A306006, A316980, A317755.

Cf. A319755, A319759, A319760, A319765, A319779, A319787, A319782, A319784, A319787.