A044356 - OEIS

%I #11 Nov 03 2025 10:48:54

%S 24,124,224,240,324,424,524,624,724,824,924,1024,1124,1224,1240,1324,

%T 1424,1524,1624,1724,1824,1924,2024,2124,2224,2240,2324,2400,2524,

%U 2624,2724,2824,2924,3024,3124,3224,3240,3324,3424,3524,3624,3724,3824,3924,4024,4124,4224

%N Numbers k such that the string 2,4 occurs in the base 10 representation of k but not of k-1.

%H Paolo Xausa, <a href="/A044356/b044356.txt">Table of n, a(n) for n = 1..10000</a>

%t A044356Q[k_] := StringContainsQ[IntegerString[k], "24"] && StringFreeQ[IntegerString[k - 1], "24"];

%t Select[Range[5000], A044356Q] (* _Paolo Xausa_, Nov 03 2025 *)

%K nonn,base

%O 1,1

%A _Clark Kimberling_

%E More terms from _Paolo Xausa_, Nov 03 2025