Number of partially achiral trees with n nodes.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =6a(6) =9a(7) =19a(8) =30a(9) =61a(10) =99a(11) =198a(12) =333a(13) =650a(14) =1115a(15) =2143a(16) =3743a(17) =7101a(18) =12553a(19) =23605a(20) =42115a(21) =78670a(22) =141284a(23) =262679a(24) =474083a(25) =878386a(26) =1591038a(27) =2940512a(28) =5340712a(29) =9852201