A318129 Number of sets of nonempty subsets of {1,...,n} with intersection {}.

1, 1, 3, 91, 31827, 2147158387, 9223372011085950171, 170141183460469231602560095290109272523, 57896044618658097711785492504343953923912733397452774312538303978325772978595

Offset: 0

Author

Gus Wiseman, Aug 18 2018

Keywords

• nonn

Examples

			The a(2) = 3 sets of sets are {}, {{1},{2}}, {{1},{2},{1,2}}.
		

Crossrefs

Cf. A000371, A001146, A003465,A040996, A119563, A131288.

Cf. A318128, A318130, A318131, A318132.

Programs

Mathematica

Table[Length[Select[Subsets[Rest[Subsets[Range[n]]]],Or[#=={},Intersection@@#=={}]&]],{n,0,4}]

Formula

Binomial transform of A318128.

a(n) = A318130(n) - 2^(2^n - 1). [corrected]