Number of series-reduced planted trees with n nodes.

Terms

a(0) =0a(1) =0a(2) =1a(3) =0a(4) =1a(5) =1a(6) =2a(7) =3a(8) =6a(9) =10a(10) =19a(11) =35a(12) =67a(13) =127a(14) =248a(15) =482a(16) =952a(17) =1885a(18) =3765a(19) =7546a(20) =15221a(21) =30802a(22) =62620a(23) =127702a(24) =261335a(25) =536278a(26) =1103600a(27) =2276499a(28) =4706985a(29) =9752585