Number of asymmetric Greg trees.

Terms

a(0) =1a(1) =1a(2) =0a(3) =0a(4) =0a(5) =0a(6) =1a(7) =4a(8) =12a(9) =42a(10) =137a(11) =452a(12) =1491a(13) =4994a(14) =16831a(15) =57408a(16) =197400a(17) =685008a(18) =2395310a(19) =8437830a(20) =29917709a(21) =106724174a(22) =382807427a(23) =1380058180a(24) =4998370015a(25) =18181067670a(26) =66393725289a(27) =243347195594a(28) =894959868983