Numbers k that divide 10^(k+1)-1.

Terms

a(0) =1a(1) =3a(2) =9a(3) =11a(4) =33a(5) =77a(6) =99a(7) =143a(8) =303a(9) =369a(10) =407a(11) =707a(12) =959a(13) =1001a(14) =1111a(15) =2439a(16) =2703a(17) =2717a(18) =2849a(19) =3107a(20) =3399a(21) =3519a(22) =4059a(23) =4277a(24) =5151a(25) =5291a(26) =6083a(27) =6439a(28) =6479a(29) =8687