A043993 Numbers k such that 6 and 7 occur juxtaposed in the base-9 representation of k but not of k+1.

61, 69, 142, 150, 223, 231, 304, 312, 385, 393, 466, 474, 547, 557, 629, 636, 709, 717, 790, 798, 871, 879, 952, 960, 1033, 1041, 1114, 1122, 1195, 1203, 1276, 1286, 1358, 1365, 1438, 1446, 1519, 1527, 1600, 1608, 1681, 1689

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 9], {6, 7}]>0||SequenceCount[ IntegerDigits[ n, 9], {7, 6}]>0, 1, 0], {n, 1700}], {1, 0}][[;; , 1]] (* Harvey P. Dale, Aug 13 2024 *)

Crossrefs

Cf. A007095.

Sequence in context: A090154 A039390 A043213 * A165287 A064229 A180555

Adjacent sequences: A043990 A043991 A043992 * A043994 A043995 A043996

Keyword

nonn,base,changed

Author

Clark Kimberling

Status

approved