Smallest k such that the concatenation from 1 to k and back to 1 is divisible by 2n-1, or 0 if no such k exists.

A120008

Smallest k such that the concatenation from 1 to k and back to 1 is divisible by 2n-1, or 0 if no such k exists.

Terms

    a(0) =1a(1) =3a(2) =0a(3) =6a(4) =3a(5) =2a(6) =6a(7) =0a(8) =109a(9) =103a(10) =6a(11) =100001a(12) =0a(13) =9a(14) =1006a(15) =17a(16) =6a(17) =0a(18) =3a(19) =6a(20) =5a(21) =103a(22) =0a(23) =1000002a(24) =6a(25) =129a(26) =100012a(27) =0

External references