A043922 Numbers k such that 2 and 3 occur juxtaposed in the base-7 representation of k but not of k+1.

17, 23, 66, 72, 115, 125, 167, 170, 213, 219, 262, 268, 311, 317, 360, 366, 409, 415, 458, 468, 510, 513, 556, 562, 605, 611, 654, 660, 703, 709, 752, 758, 801, 811, 881, 899, 905, 948, 954, 997, 1003, 1046, 1052, 1095, 1101

Offset

1,1

Links

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

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 7], {2, 3}]>0|| SequenceCount[IntegerDigits[n, 7], {3, 2}]>0, 1, 0], {n, 1200}], {1, 0}][[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Feb 15 2020 *)

Crossrefs

Cf. A007093.

Sequence in context: A214493 A039319 A043142 * A260179 A100473 A060252

Adjacent sequences: A043919 A043920 A043921 * A043923 A043924 A043925

Keyword

nonn,base

Author

Clark Kimberling

Status

approved