Number of partially achiral rooted trees.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =8a(5) =16a(6) =31a(7) =62a(8) =120a(9) =236a(10) =454a(11) =884a(12) =1697a(13) =3275a(14) =6266a(15) =12020a(16) =22935a(17) =43788a(18) =83325a(19) =158516a(20) =300914a(21) =570794a(22) =1081157a(23) =2045934a(24) =3867617a(25) =7304149a(26) =13783221a(27) =25984936a(28) =48956715a(29) =92155376