A044291 Numbers k such that the string 4,4 occurs in the base 9 representation of k but not of k-1.

40, 121, 202, 283, 360, 445, 526, 607, 688, 769, 850, 931, 1012, 1089, 1174, 1255, 1336, 1417, 1498, 1579, 1660, 1741, 1818, 1903, 1984, 2065, 2146, 2227, 2308, 2389, 2470, 2547, 2632, 2713, 2794, 2875, 2956, 3037, 3118, 3199, 3240, 3361, 3442, 3523, 3604, 3685, 3766

Offset

1,1

Links

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

Mathematica

A044291Q[k_] := StringContainsQ[IntegerString[k, 9], "44"] && StringFreeQ[IntegerString[k - 1, 9], "44"];
Select[Range[5000], A044291Q] (* Paolo Xausa, Oct 03 2025 *)

Crossrefs

Cf. A007095.

Sequence in context: A185762 A234914 A043470 * A044672 A044969 A300536

Adjacent sequences: A044288 A044289 A044290 * A044292 A044293 A044294

Keyword

nonn,base

Author

Clark Kimberling

Extensions

More terms from Paolo Xausa, Oct 03 2025

Status

approved