Number of ordered trees with n edges and having no branches of length 1.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =2a(5) =3a(6) =6a(7) =11a(8) =22a(9) =43a(10) =87a(11) =176a(12) =362a(13) =748a(14) =1560a(15) =3270a(16) =6897a(17) =14613a(18) =31104a(19) =66459a(20) =142518a(21) =306603a(22) =661572a(23) =1431363a(24) =3104619a(25) =6749390a(26) =14704387a(27) =32098729a(28) =70198656a(29) =153785705