A304984 Number of labeled clutters (connected antichains) spanning some subset of {1,...,n} with singleton edges allowed.

1, 2, 7, 56, 1533, 210302, 496838435, 309068803876372, 14369391923126181310256825

Offset: 0

Author

Gus Wiseman, May 23 2018

Keywords

• nonn

Examples

			The a(2) = 7 clutters:
  {}
  {{1}}
  {{2}}
  {{1,2}}
  {{1},{1,2}}
  {{2},{1,2}}
  {{1},{2},{1,2}}
		

Crossrefs

Cf. A048143, A198085, A261006, A304912, A304981, A304982, A304983, A304984, A304985, A304986.

Formula

Binomial transform of A304985(n > 0).