Sequence satisfies T(T(a))=a, where T is defined below.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =2a(5) =3a(6) =4a(7) =4a(8) =5a(9) =6a(10) =7a(11) =8a(12) =9a(13) =10a(14) =11a(15) =14a(16) =15a(17) =17a(18) =20a(19) =21a(20) =25a(21) =29a(22) =31a(23) =35a(24) =39a(25) =43a(26) =48a(27) =53a(28) =57a(29) =62