A044169 Numbers k such that string 4,3 occurs in the base 7 representation of k but not of k-1.

31, 80, 129, 178, 217, 227, 276, 325, 374, 423, 472, 521, 560, 570, 619, 668, 717, 766, 815, 864, 903, 913, 962, 1011, 1060, 1109, 1158, 1207, 1246, 1256, 1305, 1354, 1403, 1452, 1501, 1519, 1589, 1599, 1648, 1697, 1746, 1795, 1844, 1893, 1932, 1942, 1991, 2040, 2089, 2138

Offset

1,1

Links

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

Mathematica

A044169Q[k_] := StringContainsQ[IntegerString[k, 7], "43"] && StringFreeQ[IntegerString[k - 1, 7], "43"];
Select[Range[5000], A044169Q] (* Paolo Xausa, Sep 08 2025 *)

Crossrefs

Cf. A007093.

Sequence in context: A139901 A242777 A252231 * A044550 A055810 A142522

Adjacent sequences: A044166 A044167 A044168 * A044170 A044171 A044172

Keyword

nonn,base

Author

Clark Kimberling

Extensions

More terms from Paolo Xausa, Sep 08 2025

Status

approved