Number of ways of placing kings with no more than 4 mutual attacks on an n X n chessboard symmetric about both diagonal and antidiagonal.
A143890
Number of ways of placing kings with no more than 4 mutual attacks on an n X n chessboard symmetric about both diagonal and antidiagonal.
Terms
- a(0) =1a(1) =2a(2) =3a(3) =9a(4) =16a(5) =61a(6) =143a(7) =802a(8) =2265a(9) =17236a(10) =59156a(11) =631443a(12) =2686969a(13) =39237301a(14) =210001256
External references
- oeis: A143890