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A043923 Numbers k such that 2 and 4 occur juxtaposed in the base-7 representation of k but not of k+1. 0
18, 30, 67, 79, 116, 132, 165, 177, 216, 226, 263, 275, 312, 324, 361, 373, 410, 422, 459, 475, 508, 520, 559, 569, 606, 618, 655, 667, 704, 716, 753, 765, 802, 818, 851, 863, 930, 949, 961, 998, 1010, 1047, 1059, 1096, 1108 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

Transpose[SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 7], {2, 4}]>0 || SequenceCount[IntegerDigits[n, 7], {4, 2}]>0, 1, 0], {n, 1200}], {1, 0}]][[1]] (* The program uses the SequencePosition and SequenceCount functions from Mathematica version 10 *) (* Harvey P. Dale, Mar 10 2016 *)

CROSSREFS

Cf. A007093.

Sequence in context: A141115 A039320 A043143 * A160916 A091896 A101140

Adjacent sequences: A043920 A043921 A043922 * A043924 A043925 A043926

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified December 9 00:20 EST 2022. Contains 358698 sequences. (Running on oeis4.)