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A043924 Numbers k such that 2 and 5 occur juxtaposed in the base-7 representation of k but not of k+1. 0
19, 37, 68, 86, 117, 139, 166, 184, 215, 233, 265, 282, 313, 331, 362, 380, 411, 429, 460, 482, 509, 527, 558, 576, 608, 625, 656, 674, 705, 723, 754, 772, 803, 825, 852, 870, 901, 919, 979, 999, 1017, 1048, 1066, 1097, 1115 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 7], {2, 5}]>0 || SequenceCount[IntegerDigits[n, 7], {5, 2}]>0, 1, 0], {n, 1200}], {1, 0}] [[All, 1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 08 2020 *)

CROSSREFS

Cf. A007093.

Sequence in context: A154944 A039321 A043144 * A301617 A211821 A061237

Adjacent sequences:  A043921 A043922 A043923 * A043925 A043926 A043927

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified November 26 10:43 EST 2022. Contains 358356 sequences. (Running on oeis4.)