A081549 a(1) = 1; for n > 1, a(n) > a(n-1) is the smallest number such that the concatenation a(1)a(2)a(3)... forms a cyclic concatenation of 123456789 (of nonzero digits).

1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 34, 56, 78, 91, 234, 567, 891, 2345, 6789, 12345, 67891, 234567, 891234, 5678912, 34567891, 234567891, 2345678912, 3456789123, 4567891234, 5678912345, 6789123456, 7891234567, 8912345678, 9123456789

Offset: 1

Author

Amarnath Murthy, Apr 01 2003

Keywords

• base
• easy
• nonn

Links

• Ivan Neretin, Table of n, a(n) for n = 1..500

Crossrefs

Cf. A165307 (non-monotonic version), A007923 (version with strictly increasing length).

Programs

Mathematica

a = {1}; c = 0; Do[c = 10 c + Mod[n, 9] + 1; If[c > a[[-1]], AppendTo[a, c]; c = 0], {n, 170}]; a (* Ivan Neretin, Aug 14 2015 *)

Extensions

Corrected and extended by Sean A. Irvine, Apr 18 2010