Binary and decimal representation of n concatenated.

Terms

a(0) =11a(1) =102a(2) =113a(3) =1004a(4) =1015a(5) =1106a(6) =1117a(7) =10008a(8) =10019a(9) =101010a(10) =101111a(11) =110012a(12) =110113a(13) =111014a(14) =111115a(15) =1000016a(16) =1000117a(17) =1001018a(18) =1001119a(19) =1010020a(20) =1010121a(21) =1011022a(22) =1011123a(23) =1100024a(24) =1100125a(25) =1101026a(26) =1101127a(27) =1110028a(28) =1110129a(29) =1111030