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A289011
Fixed point of the mapping 00->0010, 01->001, 10->100, starting with 00.
4
0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0
OFFSET
1
COMMENTS
The number of letters (0's and 1's) in the n-th iterate of the mapping is given by A289010.
LINKS
EXAMPLE
The first seven iterates of the mapping:
00
0010
0010100
00101001000
001010010000100100
0010100100001001000101000010010
0010100100001001000101000010010001001001000101000010
MATHEMATICA
z = 11; (* number of iterates *)
s = {0, 0}; w[0] = StringJoin[Map[ToString, s]];
w[n_] := StringReplace[w[n - 1], {"00" -> "0010", "01" -> "001", "10" -> "100"}]
TableForm[Table[w[n], {n, 0, 10}]]
st = ToCharacterCode[w[z]] - 48 (* A289011 *)
Flatten[Position[st, 0]] (* A289012 *)
Flatten[Position[st, 1]] (* A289013 *)
Table[StringLength[w[n]], {n, 0, 20}] (* A289000 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jun 26 2017
STATUS
approved