Numbers of the form (10^(m*r)-1)/(10^r-1) for positive integers m, r.

Terms

a(0) =1a(1) =11a(2) =101a(3) =111a(4) =1001a(5) =1111a(6) =10001a(7) =10101a(8) =11111a(9) =100001a(10) =111111a(11) =1000001a(12) =1001001a(13) =1010101a(14) =1111111a(15) =10000001a(16) =11111111a(17) =100000001a(18) =100010001a(19) =101010101a(20) =111111111a(21) =1000000001a(22) =1001001001a(23) =1111111111a(24) =10000000001a(25) =10000100001a(26) =10101010101a(27) =11111111111