A044290 - OEIS

A044290

Numbers k such that the string 4,3 occurs in the base 9 representation of k but not of k-1.

%I #9 Oct 02 2025 10:35:07

%S 39,120,201,282,351,363,444,525,606,687,768,849,930,1011,1080,1092,

%T 1173,1254,1335,1416,1497,1578,1659,1740,1809,1821,1902,1983,2064,

%U 2145,2226,2307,2388,2469,2538,2550,2631,2712,2793,2874,2955,3036,3117,3159,3267,3279,3360

%N Numbers k such that the string 4,3 occurs in the base 9 representation of k but not of k-1.

%H Paolo Xausa, <a href="/A044290/b044290.txt">Table of n, a(n) for n = 1..10000</a>

%t A044290Q[k_] := StringContainsQ[IntegerString[k, 9], "43"] && StringFreeQ[IntegerString[k - 1, 9], "43"];

%t Select[Range[5000], A044290Q] (* _Paolo Xausa_, Oct 02 2025 *)

%Y Cf. A007095.

%K nonn,base

%O 1,1

%A _Clark Kimberling_

%E More terms from _Paolo Xausa_, Oct 02 2025