|
%I #6 Sep 12 2015 11:00:25
%S 1,2,6,24,120,720,3720,22336,153796,1213344,10849504,108891704,
%T 1023690268,10593791168,119694887008,1472935989952
%N Number of ways to place n nonattacking composite pieces rook + rider[4,6] on an n X n chessboard.
%C a(n) is also number of permutations p of 1,2,...,n satisfying |p(i+4k)-p(i)|<>6k AND |p(j+6k)-p(j)|<>4k for all i>=1, j>=1, k>=1, i+4k<=n, j+6k<=n
%H V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Number of ways of placing non-attacking queens, kings, bishops and knights</a> (in English and Czech)
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Fairy_chess_piece">Fairy chess piece</a>
%Y Cf. A000170, A189853, A189857, A189860
%K nonn,hard
%O 1,2
%A _Vaclav Kotesovec_, Apr 29 2011
|
