OFFSET
1,2
COMMENTS
The lace must follow a Hamiltonian path through the 2n eyelets and cannot pass in order though three adjacent eyelets that are in a line.
The lace is "undirected": reversing the order of eyelets along the path does not count as a different solution (cf. A078629).
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Dec 16 2002
STATUS
approved