A043130 Numbers k such that 4 and 5 occur juxtaposed in the base-6 representation of k but not of k-1.

29, 34, 65, 70, 101, 106, 137, 142, 173, 204, 214, 245, 250, 281, 286, 317, 322, 353, 358, 389, 420, 430, 461, 466, 497, 502, 533, 538, 569, 574, 605, 636, 646, 677, 682, 713, 718, 749, 754, 785, 790, 821, 852, 862, 893, 898

Offset

1,1

Links

Table of n, a(n) for n=1..46.

Mathematica

n45Q[n_]:=Module[{idn6=IntegerDigits[n, 6]}, SequenceCount[idn6, {4, 5}]>0 || SequenceCount[idn6, {5, 4}]>0]; Transpose[SequencePosition[Table[ If[ n45Q[k], 1, 0], {k, 1000}], {0, 1}]][[2]] (* The program uses the SequenceCount and SequencePosition functions from Mathematica version 10 *) (* Harvey P. Dale, Aug 09 2015 *)

Crossrefs

Cf. A007092.

Sequence in context: A280643 A102527 A039307 * A043910 A278329 A172413

Adjacent sequences: A043127 A043128 A043129 * A043131 A043132 A043133

Keyword

nonn,base

Author

Clark Kimberling

Status

approved