OFFSET
0,2
COMMENTS
Rectangular space-fill from Peano space-fill by row permutation of the digraph matrix: Characteristic polynomial: x^4-3*x^3-3*x+9.
LINKS
F. M. Dekking, Recurrent Sets, Advances in Mathematics, vol. 44, no.1, April 1982, page 85, section 4.1.
FORMULA
1->{1, 2, 1}, 2->{3, 4, 3}, 3->{4, 3, 4}, 4->{2, 1, 2}
MATHEMATICA
Flatten[ Nest[ Flatten[ # /. {1 -> {1, 2, 1}, 2 -> {3, 4, 3}, 3 -> {4, 3, 4}, 4 -> {2, 1, 2}}] &, {1}, 4]] (* Robert G. Wilson v *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Roger L. Bagula, May 03 2005
EXTENSIONS
Edited by Robert G. Wilson v, Jan 24 2006
STATUS
approved