OFFSET
0,1
COMMENTS
Also a(n) is the least significant nonzero digit in the radix-7 expansion of (n+1).
The sequence, interpreted as left/right turns by 120 degrees (each turn followed by a unit line in the current direction) defines a space-filling curve (called R7-dragon in the fxtbook, see link below).
Also sequence of zeros and ones by morphism F->F0F1F1F0F0F1F, 0->0, 1->1.
LINKS
Joerg Arndt: Matters Computational (The Fxtbook) (section 1.31.5 "Dragon curves based on radix-R counting", pp. 95-101, image on p. 97).
MATHEMATICA
Nest[Flatten[#/.{0->{0, 1, 0, 0, 1, 1, 0}, 1->{0, 1, 1, 0, 1, 1, 0}}]&, 0, 3] (* Harvey P. Dale, Mar 27 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Joerg Arndt, Apr 16 2010
STATUS
approved