a(n) is the negabinary expansion of n, that is, the expansion of n in base -2.

Terms

a(0) =0a(1) =1a(2) =110a(3) =111a(4) =100a(5) =101a(6) =11010a(7) =11011a(8) =11000a(9) =11001a(10) =11110a(11) =11111a(12) =11100a(13) =11101a(14) =10010a(15) =10011a(16) =10000a(17) =10001a(18) =10110a(19) =10111a(20) =10100a(21) =10101a(22) =1101010a(23) =1101011a(24) =1101000a(25) =1101001a(26) =1101110a(27) =1101111a(28) =1101100a(29) =1101101