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

1,2

Links

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

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 *)

Crossrefs

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

Sequence in context: A290388 A302504 A165307 * A085889 A342951 A342264

Adjacent sequences: A081546 A081547 A081548 * A081550 A081551 A081552

Keyword

base,easy,nonn

Author

Amarnath Murthy, Apr 01 2003

Extensions

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

Status

approved