Number of unlabeled hypertrees with up to n vertices and without singleton edges.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =17a(6) =39a(7) =98a(8) =263a(9) =759a(10) =2299a(11) =7259a(12) =23649a(13) =79057a(14) =269629a(15) =935328a(16) =3290260a(17) =11714285a(18) =42139053a(19) =152963037a(20) =559697097a(21) =2062574000a(22) =7649550572a(23) =28534096988a(24) =106994891146a(25) =403119433266