Number of rooted unlabeled trees where the root node has degree 2 and both branches are distinct.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =2a(5) =6a(6) =14a(7) =37a(8) =92a(9) =239a(10) =613a(11) =1607a(12) =4215a(13) =11185a(14) =29814a(15) =80070a(16) =216061a(17) =586218a(18) =1597292a(19) =4370721a(20) =12003163a(21) =33077327a(22) =91431425a(23) =253454781a(24) =704425087a(25) =1962537755a(26) =5479843060a(27) =15332668869a(28) =42983623237a(29) =120716987723