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A143872
Number of ways of placing kings with no more than 1 mutual attack on an n X n chessboard symmetric about main diagonal.
1
1, 2, 5, 15, 62, 329, 2307, 21482, 264021, 4334045, 94435970, 2750500857, 106769182533
OFFSET
0,2
CROSSREFS
Sequence in context: A030829 A030807 A030837 * A130756 A078793 A201702
KEYWORD
nonn,more,hard
AUTHOR
R. H. Hardin, Sep 04 2008
STATUS
approved