Sequence A115801 in binary.

Terms

a(0) =0a(1) =1111a(2) =11110a(3) =11111a(4) =111100a(5) =111110a(6) =111111a(7) =1111000a(8) =1111100a(9) =1111110a(10) =1111111a(11) =11110000a(12) =11111000a(13) =11111100a(14) =11111110a(15) =11111111a(16) =111100000a(17) =111110000a(18) =111111000a(19) =111111100a(20) =111111110a(21) =111111111a(22) =1111000000