A043913 Numbers k such that 0 and 3 occur juxtaposed in the base-7 representation of k but not of k+1.

21, 52, 70, 101, 119, 153, 168, 199, 217, 248, 266, 297, 315, 346, 370, 395, 413, 444, 462, 496, 511, 542, 560, 591, 609, 640, 658, 689, 713, 738, 756, 787, 805, 839, 854, 885, 903, 934, 952, 983, 1001, 1077, 1081, 1099, 1130

Offset

1,1

Links

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

Mathematica

jQ[n_]:=Module[{idn7=IntegerDigits[n, 7]}, Max[SequenceCount[idn7, {0, 3}], SequenceCount[idn7, {3, 0}]]>0]; Transpose[ SequencePosition[ Table[ If[ jQ[n], 1, 0], {n, 1200}], {1, 0}]][[1]] (* The program uses the SequenceCount and SequencePosition functions from Mathematica version 10 *) (* Harvey P. Dale, Oct 26 2015 *)

Crossrefs

Cf. A007093.

Sequence in context: A176588 A043133 A039310 * A280914 A347837 A304517

Adjacent sequences: A043910 A043911 A043912 * A043914 A043915 A043916

Keyword

nonn,base

Author

Clark Kimberling

Status

approved