A043136 Numbers k such that 0 and 6 occur juxtaposed in the base-7 representation of k but not of k-1.

42, 55, 91, 104, 140, 153, 189, 202, 238, 251, 287, 294, 336, 349, 385, 398, 434, 447, 483, 496, 532, 545, 581, 594, 630, 637, 679, 692, 728, 741, 777, 790, 826, 839, 875, 888, 924, 937, 973, 980, 1022, 1035, 1071, 1084, 1120

Offset

1,1

Links

Table of n, a(n) for n=1..45.

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 7], {0, 6}]>0 || SequenceCount[ IntegerDigits[n, 7], {6, 0}]>0, 1, 0], {n, 1200}], {0, 1}][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 24 2018 *)

Crossrefs

Cf. A007093.

Sequence in context: A029695 A307986 A143226 * A039313 A043916 A124656

Adjacent sequences: A043133 A043134 A043135 * A043137 A043138 A043139

Keyword

nonn,base

Author

Clark Kimberling

Status

approved