A044177 Numbers k such that string 5,4 occurs in the base 7 representation of k but not of k-1.

39, 88, 137, 186, 235, 273, 284, 333, 382, 431, 480, 529, 578, 616, 627, 676, 725, 774, 823, 872, 921, 959, 970, 1019, 1068, 1117, 1166, 1215, 1264, 1302, 1313, 1362, 1411, 1460, 1509, 1558, 1607, 1645, 1656, 1705, 1754, 1803, 1852, 1901, 1911, 1988, 1999, 2048, 2097, 2146

Offset

1,1

Links

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

Mathematica

A044177Q[k_] := StringContainsQ[IntegerString[k, 7], "54"] && StringFreeQ[IntegerString[k - 1, 7], "54"];
Select[Range[5000], A044177Q] (* Paolo Xausa, Sep 08 2025 *)

Crossrefs

Cf. A007093.

Sequence in context: A354227 A063335 A020264 * A044558 A242181 A020168

Adjacent sequences: A044174 A044175 A044176 * A044178 A044179 A044180

Keyword

nonn,base

Author

Clark Kimberling

Extensions

More terms from Paolo Xausa, Sep 08 2025

Status

approved