Number of open knight's tour diagrams of a 3 X n chessboard that are symmetric under 180-degree rotation and have "type X": both endpoints occur in the same column.
A169773
Number of open knight's tour diagrams of a 3 X n chessboard that are symmetric under 180-degree rotation and have "type X": both endpoints occur in the same column.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =4a(6) =0a(7) =0a(8) =0a(9) =16a(10) =0a(11) =0a(12) =0a(13) =264a(14) =0a(15) =0a(16) =0a(17) =2144a(18) =0a(19) =0a(20) =0a(21) =22408a(22) =0a(23) =0a(24) =0a(25) =211808a(26) =0a(27) =0a(28) =0a(29) =2087344
External references
- oeis: A169773