a(n) = 1 + a(floor(n/2))*a(ceiling(n/2)).

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =7a(5) =10a(6) =16a(7) =26a(8) =36a(9) =50a(10) =71a(11) =101a(12) =161a(13) =257a(14) =417a(15) =677a(16) =937a(17) =1297a(18) =1801a(19) =2501a(20) =3551a(21) =5042a(22) =7172a(23) =10202a(24) =16262a(25) =25922a(26) =41378a(27) =66050a(28) =107170a(29) =173890