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A293993 Number of unlabeled multiset antichains of weight n. 46

%I

%S 1,1,3,6,16,35,98,242,690

%N Number of unlabeled multiset antichains of weight n.

%C A multiset antichain is a finite set of finite nonempty multisets, none of which is a submultiset of any other. The weight of an antichain is the sum of cardinalities (counting multiplicity) of its elements.

%F Euler transform of A293994.

%e Non-isomorphic representatives of the a(4) = 16 antichains are:

%e ((1111)), ((1112)), ((1122)), ((1123)), ((1234)),

%e ((1)(234)), ((2)(111)), ((2)(113)), ((11)(12)), ((11)(22)), ((11)(23)), ((12)(13)), ((12)(34)),

%e ((1)(2)(34)),((2)(3)(11)),

%e ((1)(2)(3)(4)).

%Y Cf. A007716, A285572, A293606, A293994.

%K nonn,more

%O 0,3

%A _Gus Wiseman_, Oct 21 2017

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Last modified June 18 01:16 EDT 2021. Contains 345098 sequences. (Running on oeis4.)