A045538 Smallest number k such that kn contains two consecutive digits which are the same.

11, 11, 11, 11, 11, 11, 11, 11, 11, 10, 1, 12, 9, 8, 15, 7, 7, 8, 6, 5, 16, 1, 5, 6, 4, 13, 37, 4, 4, 10, 5, 7, 1, 13, 13, 4, 3, 3, 3, 5, 13, 8, 8, 1, 5, 7, 4, 3, 9, 2, 5, 17, 9, 21, 1, 2, 2, 2, 2, 5, 2, 9, 7, 7, 7, 1, 5, 8, 8, 10, 5, 2, 7, 3, 3, 3, 1, 15, 7, 5, 14, 13, 2, 4, 3, 4, 6, 1, 5, 10, 5

Offset

1,1

Links

Table of n, a(n) for n=1..91.

Mathematica

snk[n_]:=Module[{k=1}, While[!MemberQ[Differences[IntegerDigits[k*n]], 0], k++]; k]; Array[snk, 100] (* Harvey P. Dale, May 04 2013 *)

Crossrefs

Sequence in context: A100755 A171902 A337241 * A084066 A231472 A319150

Adjacent sequences: A045535 A045536 A045537 * A045539 A045540 A045541

Keyword

base,nonn

Author

Erich Friedman

Status

approved