Number of nonisomorphic open quipus with n nodes.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =2a(6) =4a(7) =6a(8) =11a(9) =18a(10) =36a(11) =64a(12) =127a(13) =241a(14) =480a(15) =935a(16) =1868a(17) =3688a(18) =7373a(19) =14655a(20) =29305a(21) =58432a(22) =116859a(23) =233367a(24) =466727a(25) =932761a(26) =1865513a(27) =3729648a(28) =7459286a(29) =14915826