Number of ways of placing kings with no more than 2 mutual attacks on an n X n chessboard symmetric under 180 degree rotation.

A143880

Number of ways of placing kings with no more than 2 mutual attacks on an n X n chessboard symmetric under 180 degree rotation.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =15a(4) =36a(5) =383a(6) =1505a(7) =28764a(8) =197391a(9) =6544311a(10) =74718810

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