Number of integers in n-th generation of tree T(5/2) defined in Comments.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =4a(6) =5a(7) =8a(8) =12a(9) =19a(10) =27a(11) =41a(12) =60a(13) =90a(14) =136a(15) =204a(16) =306a(17) =461a(18) =692a(19) =1036a(20) =1557a(21) =2330a(22) =3498a(23) =5247a(24) =7872a(25) =11803a(26) =17715a(27) =26558a(28) =39851a(29) =59781