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%I #10 Mar 30 2012 16:50:47
%S 123,12123,12323,123123,1212123,1212323,1232323,12123123,12312123,
%T 12312323,12313123,12323123,121212123,121212323,121232123,121232323,
%U 123123123,123212323,123232323,1212123123,1212312123,1212312323,1212313123,1212323123,1231212123
%N Sorted list of primitive strings that can be obtained by starting with 123 and repeatedly doubling any substring in place.
%C The list contains A135017(n) strings of length n.
%C The subset of strings in A135475 that contain no repeated symbol.
%H Alois P. Heinz, <a href="/A135479/b135479.txt">Table of n, a(n) for n = 1..11498</a>
%H <a href="/index/Do#repeat">Index entries for doubling substrings</a>
%K nonn,easy
%O 1,1
%A _N. J. A. Sloane_, Feb 22 2008