Second differences of Thue-Morse sequence A001285.

Terms

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