a(n+1) = Sum_{k=0..floor(3*n/4)} a(k) * a(n-k).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =9a(6) =17a(7) =38a(8) =89a(9) =213a(10) =480a(11) =1151a(12) =2810a(13) =6978a(14) =16497a(15) =40731a(16) =101680a(17) =256491a(18) =623916a(19) =1568966a(20) =3972773a(21) =10130647a(22) =25044032a(23) =63573638a(24) =162478685a(25) =417322917a(26) =1049096179a(27) =2687278965a(28) =6917001254a(29) =17882746627