Sequence A115876 in binary.

Terms

a(0) =0a(1) =111a(2) =1110a(3) =11100a(4) =111000a(5) =1110000a(6) =11100000a(7) =111000000a(8) =1110000000a(9) =11100000000a(10) =111000000000a(11) =111000000111