Period 4 zigzag sequence: repeat [0,1,2,1].

Terms

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