Period 2: repeat [0, 1]; a(n) = n mod 2; parity of n.

Terms

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