%I #18 May 11 2021 05:25:50
%S 1,12,123,1234,12345,123456,1234567,12345678,123456789,1023456789,
%T 11023456789,101123456789,1011213456789,10112131456789,
%U 101121314156789,1011213141516789,10112131415161789,101121314151617189
%N Smallest number that contains the numbers from 1 to n as substrings.
%H D. Rusin, <a href="https://web.archive.org/web/20120721032225/http://www.math.niu.edu:80/~rusin/known-math/95/1000digits">Solution for n=1000</a>
%H D. Rusin, <a href="/A035239/a035239.txt">Solution for n=1000</a> [Cached copy]
%Y Cf. A054260, A054261, A056744.
%K easy,nonn,base
%O 1,2
%A _Erich Friedman_
%E Keyword base added by _Reinhard Zumkeller_, May 16 2010