A044251 Numbers k such that string 0,0 occurs in the base 9 representation of k but not of k-1.

81, 162, 243, 324, 405, 486, 567, 648, 729, 810, 891, 972, 1053, 1134, 1215, 1296, 1377, 1458, 1539, 1620, 1701, 1782, 1863, 1944, 2025, 2106, 2187, 2268, 2349, 2430, 2511, 2592, 2673, 2754, 2835, 2916, 2997, 3078, 3159

Offset

1,1

Comments

Every element is a multiple of 81. The smallest positive multiple of 81 not in the sequence is 6642. - David W. Wilson, Aug 03 2005

Links

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

Tanya Khovanova, Non Recursions

Mathematica

A044251Q[k_] := StringContainsQ[IntegerString[k, 9], "00"] && StringFreeQ[IntegerString[k - 1, 9], "00"];
Select[Range[5000], A044251Q] (* Paolo Xausa, Sep 02 2025 *)

Crossrefs

Sequence in context: A226643 A391077 A353456 * A043454 A044632 A031494

Adjacent sequences: A044248 A044249 A044250 * A044252 A044253 A044254

Keyword

nonn,base

Author

Clark Kimberling

Status

approved