A044312 Numbers n such that string 6,7 occurs in the base 9 representation of n but not of n-1.

61, 142, 223, 304, 385, 466, 547, 549, 628, 709, 790, 871, 952, 1033, 1114, 1195, 1276, 1278, 1357, 1438, 1519, 1600, 1681, 1762, 1843, 1924, 2005, 2007, 2086, 2167, 2248, 2329, 2410, 2491, 2572, 2653, 2734, 2736, 2815

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

Select[Range[5000], MemberQ[Partition[IntegerDigits[#, 9], 2, 1], {6, 7}] && !MemberQ[Partition[IntegerDigits[#-1, 9], 2, 1], {6, 7}]&] (* Harvey P. Dale, May 12 2012 *)
SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 9], {6, 7}]>0, 1, 0], {n, 3000}], {0, 1}][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 02 2021 *)

Crossrefs

Sequence in context: A306750 A142172 A168023 * A044693 A185662 A140726

Adjacent sequences: A044309 A044310 A044311 * A044313 A044314 A044315

Keyword

nonn,base

Author

Clark Kimberling

Status

approved