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.

1, 3, 0, 6, 3, 2, 6, 0, 109, 103, 6, 100001, 0, 9, 1006, 17, 6, 0, 3, 6, 5, 103, 0, 1000002, 6, 129, 100012, 0

Offset

1,2

Comments

a(29), 2n-1 = 57, is at least 1e8.

Links

Table of n, a(n) for n=1..28.

Crossrefs

Cf. A077189.

Sequence in context: A005889 A095712 A085753 * A162197 A160770 A212225

Adjacent sequences: A120005 A120006 A120007 * A120009 A120010 A120011

Keyword

base,nonn

Author

Franklin T. Adams-Watters, Jun 02 2006

Status

approved