A135475 Sorted list of strings that can be obtained by starting with 123 and repeatedly doubling any substring in place.

123, 1123, 1223, 1233, 11123, 11223, 11233, 12123, 12223, 12233, 12323, 12333, 111123, 111223, 111233, 112123, 112223, 112233, 112323, 112333, 121123, 121223, 121233, 122123, 122223, 122233, 122323, 122333, 123123, 123223, 123233, 123323, 123333, 1111123

Offset: 1

Author

N. J. A. Sloane, Feb 22 2008, Mar 16 2008

Keywords

• nonn
• easy

Comments

The list contains A135473(n) strings of length n.

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..10397 (strings with length <= 12)
• Index entries for doubling substrings

Crossrefs

Cf. A135473, A130838, A135479, A135017.