(Number of 0's) - (number of 1's) in the base-2 representation of n.

Terms

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