Working in base 2, replace n with the concatenation of its prime factors (without repetition).

Terms

a(0) =1a(1) =10a(2) =11a(3) =10a(4) =101a(5) =1011a(6) =111a(7) =10a(8) =11a(9) =10101a(10) =1011a(11) =1011a(12) =1101a(13) =10111a(14) =11101a(15) =10a(16) =10001a(17) =1011a(18) =10011a(19) =10101a(20) =11111a(21) =101011a(22) =10111a(23) =1011a(24) =101a(25) =101101a(26) =11a(27) =10111a(28) =11101a(29) =1011101