The game of contours.

Terms

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