OFFSET
0,2
LINKS
F. M. Dekking, Recurrent sets, Advances in Mathematics, vol. 44, no. 1 (1982), 78-104.
MAPLE
subs({1=[1, 2, 2, 2], 2=[2, 1, 1, 1]}, 1): subs({1=[1, 2, 2, 2], 2=[2, 1, 1, 1]}, %): subs({1=[1, 2, 2, 2], 2=[2, 1, 1, 1]}, %): subs({1=[1, 2, 2, 2], 2=[2, 1, 1, 1]}, %); # remove all brackets from the output; Emeric Deutsch, May 31 2005
MATHEMATICA
Nest[ Flatten[ # /. {1 -> {1, 2, 2, 2}, 2 -> {2, 1, 1, 1}}] &, {1}, 5] (* Robert G. Wilson v, Jun 20 2005 *)
SubstitutionSystem[{1->{1, 2, 2, 2}, 2->{2, 1, 1, 1}}, 1, 4]//Flatten (* Harvey P. Dale, Nov 20 2021 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, May 20 2005
EXTENSIONS
More terms from Emeric Deutsch, May 31 2005
STATUS
approved