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A293993 Number of unlabeled multiset antichains of weight n. 46
1, 1, 3, 6, 16, 35, 98, 242, 690 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

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.

LINKS

Table of n, a(n) for n=0..8.

FORMULA

Euler transform of A293994.

EXAMPLE

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

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

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

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

((1)(2)(3)(4)).

CROSSREFS

Cf. A007716, A285572, A293606, A293994.

Sequence in context: A327736 A319752 A130095 * A072824 A089406 A027852

Adjacent sequences:  A293990 A293991 A293992 * A293994 A293995 A293996

KEYWORD

nonn,more

AUTHOR

Gus Wiseman, Oct 21 2017

STATUS

approved

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Last modified November 20 05:07 EST 2019. Contains 329323 sequences. (Running on oeis4.)