Number of unlabeled nonempty hypertrees with up to n vertices and no singleton edges.

Terms

a(0) =1a(1) =0a(2) =1a(3) =3a(4) =7a(5) =16a(6) =38a(7) =97a(8) =262a(9) =758a(10) =2298a(11) =7258a(12) =23648a(13) =79056a(14) =269628a(15) =935327a(16) =3290259a(17) =11714284a(18) =42139052a(19) =152963036a(20) =559697096a(21) =2062573999a(22) =7649550571a(23) =28534096987a(24) =106994891145a(25) =403119433265