A130728 - OEIS

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A130728

Number of ways of placing non-attacking knights on an n X n chessboard symmetric under 90-degree rotation.

%I #6 Nov 25 2018 13:56:10

%S 1,2,2,6,3,27,28,324,338,5991,6875,228512,322056,17782554,30487207,

%T 2704389848,5451449965,819155081866,1981437279113,497332226754331,

%U 1457925225531230,603767469974886673,2133983730438871395

%N Number of ways of placing non-attacking knights on an n X n chessboard symmetric under 90-degree rotation.

%K nonn

%O 0,2

%A _R. H. Hardin_, Aug 25 2008