Number of series-reduced balanced trees with n leaves.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =4a(6) =4a(7) =8a(8) =9a(9) =16a(10) =20a(11) =37a(12) =47a(13) =80a(14) =111a(15) =183a(16) =256a(17) =413a(18) =591a(19) =940a(20) =1373a(21) =2159a(22) =3214a(23) =5067a(24) =7649a(25) =12054a(26) =18488a(27) =29203a(28) =45237a(29) =71566