A043146 Numbers k such that 3 and 4 occur juxtaposed in the base-7 representation of k but not of k-1.

25, 31, 74, 80, 123, 129, 172, 175, 217, 227, 270, 276, 319, 325, 368, 374, 417, 423, 466, 472, 515, 518, 560, 570, 613, 619, 662, 668, 711, 717, 760, 766, 809, 815, 858, 861, 903, 913, 956, 962, 1005, 1011, 1054, 1060, 1103

Offset

1,1

Links

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

Mathematica

SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 7], {3, 4}]>0 || SequenceCount[ IntegerDigits[n, 7], {4, 3}]>0, 1, 0], {n, 1200}], {0, 1}][[;; , 2]] (* Harvey P. Dale, May 09 2023 *)

Crossrefs

Cf. A007093.

Sequence in context: A157646 A198003 A039323 * A043926 A202000 A118669

Adjacent sequences: A043143 A043144 A043145 * A043147 A043148 A043149

Keyword

nonn,base

Author

Clark Kimberling

Status

approved