Number of non-isomorphic set-systems of weight n with no singletons or endpoints.

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =1a(7) =1a(8) =3a(9) =5a(10) =16a(11) =24a(12) =90a(13) =179a(14) =567a(15) =1475a(16) =4623a(17) =13650a(18) =44475a(19) =144110a(20) =492017a(21) =1706956a(22) =6124330a(23) =22442687a(24) =84406276a(25) =324298231a(26) =1273955153a(27) =5106977701a(28) =20885538133a(29) =87046940269