A318532 Number of finite sets of set partitions of {1,...,n} such that any two have meet {{1},...,{n}} and join {{1,...,n}}.

2, 4, 11, 51, 635, 15591

Offset: 1

Author

Gus Wiseman, Aug 28 2018

Keywords

• nonn
• more

Examples

			The a(3) = 11 sets of set partitions:
        0
    {{1,2,3}}
   {{1,3},{2}}
   {{1,2},{3}}
   {{1},{2,3}}
  {{1},{2},{3}}
   {{1,2},{3}}   {{1,3},{2}}
   {{1},{2,3}}   {{1,3},{2}}
   {{1},{2,3}}   {{1,2},{3}}
  {{1},{2},{3}}   {{1,2,3}}
   {{1},{2,3}}   {{1,2},{3}}  {{1,3},{2}}
		

Crossrefs

Cf. A000110, A000258, A008277, A059849, A060639, A096827, A181939.

Cf. A318389, A318390, A318391, A318392, A318394, A318531.