A043097 Numbers k such that 0 and 1 occur juxtaposed in the base-3 representation of k but not of k-1.

3, 9, 19, 21, 27, 46, 48, 55, 57, 63, 73, 75, 81, 127, 129, 136, 138, 144, 154, 156, 163, 165, 171, 181, 183, 189, 208, 210, 217, 219, 225, 235, 237, 243, 370, 372, 379, 381, 387, 397, 399, 406, 408, 414, 424, 426, 432, 451, 453

Offset

1,1

Links

Table of n, a(n) for n=1..49.

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 3], {0, 1}]>0 || SequenceCount[IntegerDigits[n, 3], {1, 0}]>0, 1, 0], {n, 500}], {0, 1}][[;; , 2]] (* Harvey P. Dale, Mar 29 2023 *)

Crossrefs

Cf. A007089.

Sequence in context: A270979 A253219 A097267 * A084670 A002091 A056259

Adjacent sequences: A043094 A043095 A043096 * A043098 A043099 A043100

Keyword

nonn,base

Author

Clark Kimberling

Status

approved