Numbers that require three steps to collapse to a single digit in base 4 (written in base 4).

Terms

a(0) =223a(1) =1213a(2) =2023a(3) =2122a(4) =2203a(5) =2221a(6) =3133a(7) =11113a(8) =12103a(9) =13033a(10) =20023a(11) =20203a(12) =20221a(13) =21202a(14) =22003a(15) =22021a(16) =22201a(17) =22333a(18) =30313a(19) =31033a(20) =31132a(21) =103033a(22) =110113a(23) =111103a(24) =113032a(25) =121003a(26) =200023a(27) =200203a(28) =200221a(29) =202003