Number of non-isomorphic set systems of weight n with empty intersection.

Terms

a(0) =1a(1) =0a(2) =1a(3) =2a(4) =6a(5) =13a(6) =35a(7) =83a(8) =217a(9) =556a(10) =1504a(11) =4103a(12) =11715a(13) =34137a(14) =103155a(15) =320217a(16) =1025757a(17) =3376889a(18) =11436712a(19) =39758152a(20) =141817521a(21) =518322115a(22) =1939518461a(23) =7422543892a(24) =29028055198a(25) =115908161428a(26) =472185530376