OFFSET
1,2
LINKS
D. Applegate, E. M. Rains and N. J. A. Sloane, On asymmetric coverings and covering numbers, arXiv:math/0205303 [math.CO], 2002; J. Comb. Des. 11 (2003), 218-228.
CROSSREFS
KEYWORD
nonn,hard,more,nice
AUTHOR
N. J. A. Sloane, Dec 07 2001
STATUS
approved