OFFSET
0,1
MATHEMATICA
z = 30; (* number of iterates *)
s = {0, 0}; w[0] = StringJoin[Map[ToString, s]];
w[n_] := StringReplace[w[n - 1], {"00" -> "0010", "01" -> "001", "10" -> "011"}]
TableForm[Table[w[n], {n, 0, 10}]]
Table[StringLength[w[n]], {n, 0, 20}] (* A289007 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jun 26 2017
STATUS
approved