A nonrepetitive sequence.

Terms

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