A044137 Numbers k such that string 5,5 occurs in the base 6 representation of k but not of k-1.

35, 71, 107, 143, 179, 210, 251, 287, 323, 359, 395, 426, 467, 503, 539, 575, 611, 642, 683, 719, 755, 791, 827, 858, 899, 935, 971, 1007, 1043, 1074, 1115, 1151, 1187, 1223, 1259, 1331, 1367, 1403, 1439, 1475, 1506, 1547, 1583, 1619, 1655, 1691, 1722, 1763, 1799, 1835

Offset

1,1

Links

Paolo Xausa, Table of n, a(n) for n = 1..10000

Mathematica

A044137Q[k_] := StringContainsQ[IntegerString[k, 6], "55"] && StringFreeQ[IntegerString[k - 1, 6], "55"];
Select[Range[5000], A044137Q] (* Paolo Xausa, Sep 10 2025 *)
SequencePosition[Table[If[SequenceCount[IntegerDigits[n, 6], {5, 5}]>0, 1, 0], {n, 2000}], {0, 1}][[;; , 2]] (* Harvey P. Dale, Apr 18 2026 *)

Crossrefs

Cf. A007092.

Sequence in context: A135802 A043390 A031481 * A350055 A044518 A039382

Adjacent sequences: A044134 A044135 A044136 * A044138 A044139 A044140

Keyword

nonn,base

Author

Clark Kimberling

Extensions

More terms from Paolo Xausa, Sep 10 2025

Status

approved