A043190 Numbers k such that 1 and 4 occur juxtaposed in the base-9 representation of k but not of k-1.

13, 37, 94, 117, 175, 199, 256, 280, 333, 361, 418, 442, 499, 523, 580, 604, 661, 685, 742, 766, 823, 846, 904, 928, 985, 1009, 1053, 1147, 1171, 1228, 1252, 1309, 1333, 1390, 1414, 1471, 1495, 1552, 1575, 1633, 1657, 1714

Offset

1,1

Links

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

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 9], {1, 4}]>0||SequenceCount[IntegerDigits[n, 9], {4, 1}]>0, 1, 0], {n, 2000}], {0, 1}][[;; , 2]] (* Harvey P. Dale, Feb 12 2025 *)

Crossrefs

Cf. A007095.

Sequence in context: A145990 A089528 A317986 * A043970 A183339 A331763

Adjacent sequences: A043187 A043188 A043189 * A043191 A043192 A043193

Keyword

nonn,base,changed

Author

Clark Kimberling

Status

approved