a(n) = round(cos(n)).

Terms

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