Unique representation of nonnegative numbers by iterated tribonacci A, B and C sequences.

Terms

a(0) =1a(1) =21a(2) =121a(3) =31a(4) =1121a(5) =221a(6) =131a(7) =11121a(8) =2121a(9) =1221a(10) =321a(11) =1131a(12) =231a(13) =111121a(14) =21121a(15) =12121a(16) =3121a(17) =11221a(18) =2221a(19) =1321a(20) =11131a(21) =2131a(22) =1231a(23) =331a(24) =1111121a(25) =211121a(26) =121121a(27) =31121a(28) =112121a(29) =22121