A044180 Numbers k such that string 6,0 occurs in the base 7 representation of k but not of k-1.

42, 91, 140, 189, 238, 287, 294, 336, 385, 434, 483, 532, 581, 630, 637, 679, 728, 777, 826, 875, 924, 973, 980, 1022, 1071, 1120, 1169, 1218, 1267, 1316, 1323, 1365, 1414, 1463, 1512, 1561, 1610, 1659, 1666, 1708, 1757, 1806, 1855, 1904, 1953, 2002, 2009, 2051, 2058, 2149

Offset

1,1

Links

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

Mathematica

A044180Q[k_] := StringContainsQ[IntegerString[k, 7], "60"] && StringFreeQ[IntegerString[k - 1, 7], "60"];
Select[Range[5000], A044180Q] (* Paolo Xausa, Sep 08 2025 *)

Crossrefs

Cf. A007093.

Sequence in context: A301328 A370521 A067296 * A044561 A169680 A177772

Adjacent sequences: A044177 A044178 A044179 * A044181 A044182 A044183

Keyword

nonn,base

Author

Clark Kimberling

Extensions

More terms from Paolo Xausa, Sep 08 2025

Status

approved