Binary string which equals n when 1's and 2's bits have negative weights.

Terms

a(0) =0a(1) =111a(2) =110a(3) =101a(4) =100a(5) =1011a(6) =1010a(7) =1001a(8) =1000a(9) =1111a(10) =1110a(11) =1101a(12) =1100a(13) =10011a(14) =10010a(15) =10001a(16) =10000a(17) =10111a(18) =10110a(19) =10101a(20) =10100a(21) =11011a(22) =11010a(23) =11001a(24) =11000a(25) =11111a(26) =11110a(27) =11101a(28) =11100a(29) =100011