|
|
A143879
|
|
Number of ways of placing kings with no more than 2 mutual attacks on an n X n chessboard symmetric about both diagonal and antidiagonal.
|
|
1
|
|
|
1, 2, 3, 7, 12, 41, 85, 434, 1009, 7325, 21498, 219307, 803859, 11370922
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more,hard
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|