A043932 Numbers k such that 0 and 1 occur juxtaposed in the base-8 representation of k but not of k+1.

8, 72, 129, 136, 193, 200, 257, 264, 321, 328, 385, 392, 449, 456, 584, 641, 648, 705, 712, 769, 776, 833, 840, 897, 904, 961, 968, 1025, 1039, 1096, 1153, 1160, 1217, 1224, 1281, 1288, 1345, 1352, 1409, 1416, 1473, 1480, 1537

Offset

1,1

Links

Table of n, a(n) for n=1..43.

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 8], {0, 1}]>0 || SequenceCount[IntegerDigits[n, 8], {1, 0}]>0, 1, 0], {n, 1600}], {1, 0}][[All, 1]] (* Harvey P. Dale, Dec 28 2021 *)

Prog

(Python)
def ok(n):
    on, onm1 = oct(n)[2:], oct(n+1)[2:]
    return ("01" in on or "10" in on) and not ("01" in onm1 or "10" in onm1)
print(list(filter(ok, range(1, 1538)))) # Michael S. Branicky, Aug 25 2021

Crossrefs

Cf. A007094.

Sequence in context: A097255 A115693 A112403 * A064015 A044576 A104453

Adjacent sequences: A043929 A043930 A043931 * A043933 A043934 A043935

Keyword

nonn,base

Author

Clark Kimberling

Status

approved