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 A075015 #5 Dec 05 2013 19:55:35
%S A075015 1,2,1,4,3,2,5,4,2,8,8,4,2,104,3,18,17,2,4,18,5,8,3,4,23,2,5,118,37,8,
%T A075015 39,18,8,34,118,14,110,4,2,18,1,104,47,10,8,32,49,18,104,48,17,142,48,
%U A075015 8,8,118,4,66,21,18,48,70,5,50
%N A075015 Smallest k such that the concatenation k, k+1, k+2 is divisible by n; or 0 if no such number exists.
%H A075015 Harvey P. Dale, <a href="/A075015/b075015.txt">Table of n, a(n) for n = 1..1000</a>
%e A075015 a(13) = 2 as 13 divides 234.
%t A075015 Table[Module[{k=1},While[!Divisible[FromDigits[Flatten[ IntegerDigits/@ Range[k,k+2]]],n],k++];k],{n,70}] (* _Harvey P. Dale_, May 10 2012 *)
%Y A075015 Cf. A075113, A075114, A075116, A075117.
%K A075015 base,nonn
%O A075015 1,2
%A A075015 _Amarnath Murthy_, Sep 01 2002
%E A075015 Corrected and extended by Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 19 2003