OFFSET
0,2
LINKS
N. J. A. Sloane, Illustration for a(4) = 20. (The largest empty region has size 8 X 5 squares, but the squares have width 1/2, so a(4) = 20.)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Scott R. Shannon and N. J. A. Sloane, Sep 14 2020
STATUS
approved