login
A143874
Number of ways of placing kings with no more than 1 mutual attack on an n X n chessboard symmetric under 180 degree rotation.
1
1, 2, 3, 7, 18, 111, 497, 4630, 38327, 702227, 10398834
OFFSET
0,2
CROSSREFS
Sequence in context: A160181 A096203 A328430 * A073641 A273006 A352538
KEYWORD
nonn,more,hard
AUTHOR
R. H. Hardin, Sep 04 2008
STATUS
approved