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 A051018 #28 Feb 16 2025 08:32:41
%S A051018 1023456789,1023456879,1023457689,1023457869,1023458679,1023458769,
%T A051018 1023465789,1023465879,1023467589,1023467859,1023468579,1023468759,
%U A051018 1023475689,1023475869,1023476589,1023476859,1023478569,1023478659,1023485679,1023485769,1023486579,1023486759
%N A051018 Numbers that are 2-persistent but not 3-persistent.
%C A051018 A number m is k-persistent iff all of {m, 2m,..., km} are pandigital (in the sense of A171102).
%H A051018 Hans Havermann, <a href="/A051018/b051018.txt">Table of n, a(n) for n = 1..1000</a>
%H A051018 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PersistentNumber.html">Persistent Number</a>
%o A051018 (PARI) is_A051018(n,k=3)=10>#Set(Vec(Str(k*n))) & !while(k--,9<#Set(Vec(Str(k*n))) || return(0)) \\ _M. F. Hasler_, Jan 10 2012
%Y A051018 Cf. A171102 (pandigital), A204047 (smallest n-persistent), A051264 (1-persistent), A051019 (3-persistent), A051020 (4-persistent), A204096 (5-persistent), A204097 (6-persistent).
%K A051018 nonn,base
%O A051018 1,1
%A A051018 _Eric W. Weisstein_
%E A051018 Definition corrected by _Franklin T. Adams-Watters_, Jan 09 2012