Least k such that the decimal representation of k*n contains only 1's and 0's.

Terms

a(0) =1a(1) =5a(2) =37a(3) =25a(4) =2a(5) =185a(6) =143a(7) =125a(8) =12345679a(9) =1a(10) =1a(11) =925a(12) =77a(13) =715a(14) =74a(15) =625a(16) =653a(17) =61728395a(18) =579a(19) =5a(20) =481a(21) =5a(22) =4787a(23) =4625a(24) =4a(25) =385a(26) =40781893a(27) =3575a(28) =37969a(29) =37