This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A118669 #10 Feb 16 2025 08:33:01
%S A118669 25,32,36,96,100,125,128,162,216,243,256,300,486,512,576,625,648,700,
%T A118669 768,864,1000,1024,1100,1215,1296,1300,1536,1700,1900,2048,2100,2300,
%U A118669 2430,2900,2916,3000,3100,3125,3300,3456,3700,3773,3900,4100,4300,4608
%N A118669 Numbers that are not squarefree, but contain their squarefree kernel in decimal representation.
%C A118669 For k>1: m*10^k are terms for squarefree numbers m coprime to 10.
%C A118669 If m is a term and coprime to 10 then also 10*m is a term.
%H A118669 Amiram Eldar, <a href="/A118669/b118669.txt">Table of n, a(n) for n = 1..10000</a>
%H A118669 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Squarefree.html">Squarefree</a>.
%t A118669 Select[Range[5000], (r = rad[#]) < # && SequenceCount @@ IntegerDigits[{#, r}] > 0 &] (* _Amiram Eldar_, Sep 07 2020 *)
%Y A118669 Cf. A005117, A013929, A007947, A076333.
%K A118669 nonn,base
%O A118669 1,1
%A A118669 _Reinhard Zumkeller_, May 19 2006