A043907 Numbers k such that 2 and 5 occur juxtaposed in the base-6 representation of k but not of k+1.

17, 32, 53, 68, 89, 107, 125, 140, 161, 176, 197, 212, 233, 248, 269, 284, 305, 323, 341, 356, 377, 392, 413, 428, 449, 464, 485, 500, 521, 539, 557, 572, 593, 608, 647, 665, 680, 701, 716, 737, 755, 773, 788, 809, 824, 845, 860

Offset

1,1

Links

Table of n, a(n) for n=1..47.

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 6], {2, 5}]>0 || SequenceCount[ IntegerDigits[n, 6], {5, 2}]>0, 1, 0], {n, 900}], {1, 0}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Sep 23 2019 *)

Crossrefs

Cf. A007092.

Sequence in context: A058899 A038354 A043127 * A173054 A162624 A029817

Adjacent sequences: A043904 A043905 A043906 * A043908 A043909 A043910

Keyword

nonn,base

Author

Clark Kimberling

Status

approved