Number of self-converse oriented trees with n nodes.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =7a(6) =10a(7) =26a(8) =39a(9) =107a(10) =160a(11) =458a(12) =702a(13) =2058a(14) =3177a(15) =9498a(16) =14830a(17) =44947a(18) =70678a(19) =216598a(20) =342860a(21) =1059952a(22) =1686486a(23) =5251806a(24) =8393681a(25) =26297238a(26) =42187148a(27) =132856766a(28) =213828802a(29) =676398395