A043930 Numbers k such that 4 and 6 occur juxtaposed in the base-7 representation of k but not of k+1.

34, 46, 83, 95, 132, 144, 181, 193, 230, 244, 279, 291, 328, 340, 377, 389, 426, 438, 475, 487, 524, 536, 573, 587, 622, 634, 671, 683, 720, 732, 769, 781, 818, 830, 867, 879, 916, 930, 965, 977, 1014, 1026, 1063, 1075, 1112

Offset

1,1

Links

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

Mathematica

Transpose[SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 7], {4, 6}]>0||SequenceCount[IntegerDigits[n, 7], {6, 4}]>0, 1, 0], {n, 1200}], {1, 0}]][[1]] (* The program uses the SequencePosition and SequenceCount functions from Mathematica version 10 *) (* Harvey P. Dale, Nov 29 2015 *)

Crossrefs

Cf. A007093.

Sequence in context: A211710 A039327 A043150 * A260277 A045256 A302002

Adjacent sequences: A043927 A043928 A043929 * A043931 A043932 A043933

Keyword

nonn,base

Author

Clark Kimberling

Status

approved