This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A293993 #5 Oct 21 2017 21:08:16 %S A293993 1,1,3,6,16,35,98,242,690 %N A293993 Number of unlabeled multiset antichains of weight n. %C A293993 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 A293993 Euler transform of A293994. %e A293993 Non-isomorphic representatives of the a(4) = 16 antichains are: %e A293993 ((1111)), ((1112)), ((1122)), ((1123)), ((1234)), %e A293993 ((1)(234)), ((2)(111)), ((2)(113)), ((11)(12)), ((11)(22)), ((11)(23)), ((12)(13)), ((12)(34)), %e A293993 ((1)(2)(34)),((2)(3)(11)), %e A293993 ((1)(2)(3)(4)). %Y A293993 Cf. A007716, A285572, A293606, A293994. %K A293993 nonn,more %O A293993 0,3 %A A293993 _Gus Wiseman_, Oct 21 2017