A156596 Infinite Fibonacci word fractal sequence.

1, 0, 1, 2, 0, 2, 0, 2, 1, 0, 1, 2, 0, 2, 0, 2, 1, 0, 1, 0, 1, 2, 0, 2, 1, 0, 1, 0, 1, 2, 0, 2, 1, 0, 1, 0, 1, 2, 0, 2, 0, 2, 1, 0, 1, 2, 0, 2, 0, 2, 1, 0, 1, 0, 1, 2, 0, 2, 1, 0, 1, 0, 1, 2, 0, 2, 1, 0, 1, 0, 1, 2, 0, 2, 0, 2, 1, 0, 1, 2, 0, 2, 0, 2, 1, 0, 1, 2, 0, 2, 0, 2, 1, 0, 1, 0, 1, 2, 0, 2, 1, 0, 1, 0, 1

Offset: 1

Author

Alexis Monnerot-Dumaine, Feb 10 2009

Keywords

• nice
• nonn

Comments

Apply to A143667 the map : 0 -> 12, 1 -> 10, 2 -> 02. or apply to A003849 (the Fibonacci word), after grouping the terms 2 by 2, the map : "00" -> "12", "01"->"10, "10"->"02". Draws the Fibonacci word fractal curve when applying the following drawing rule: if "0" then draw a segment forward, if "1" then draw a segment forward and turn 90A degs right, if "2" the draw segment and turn 90A degs left.

References

• M. Lothaire, Combinatorics on words, Cambridge University Press.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..1000
• A. Monnerot-Dumaine, Fibonacci word fractal
• Alexis Monnerot-Dumaine, The Fibonacci word fractal [Cached copy, with permission]

Crossrefs

Cf. A003849, A143667.

Programs

Haskell

a143667 n = a143667_list !! (n-1)
a143667_list = f a003849_list where
   f (0:0:ws) = 0 : f ws; f (0:1:ws) = 1 : f ws; f (1:0:ws) = 2 : f ws
-- Reinhard Zumkeller, Jul 29 2014

Mathematica

Partition[Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {0}}]&, {0}, 10], 2] /. {{0, 0} -> {1, 2}, {0, 1} -> {1, 0}, {1, 0} -> {0, 2}} // Flatten (* Jean-François Alcover, Jul 16 2015 *)