Number of binary forests with n nodes.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =6a(5) =10a(6) =20a(7) =37a(8) =76a(9) =152a(10) =320a(11) =672a(12) =1454a(13) =3154a(14) =6959a(15) =15439a(16) =34608a(17) =77988a(18) =176985a(19) =403510a(20) =924683a(21) =2127335a(22) =4913452a(23) =11385955a(24) =26468231a(25) =61700232a(26) =144206269a(27) =337837221a(28) =793213550a(29) =1866181155