Number of anti-transitive rooted identity trees with n nodes.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =4a(6) =9a(7) =20a(8) =41a(9) =89a(10) =196a(11) =443a(12) =987a(13) =2246a(14) =5114a(15) =11757a(16) =27122a(17) =62898a(18) =146392a(19) =342204a(20) =802429a(21) =1887882