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Number of ways to place n nonattacking composite pieces rook + rider[6,6] on an n X n chessboard.
1

%I #6 Sep 12 2015 11:00:25

%S 1,2,6,24,120,720,4800,34752,280512,2528256,25282560,278323200,

%T 3242649600,40330371072,536528954880,7633092132864

%N Number of ways to place n nonattacking composite pieces rook + rider[6,6] on an n X n chessboard.

%C a(n) is also number of permutations p of 1,2,...,n satisfying |p(j+6k)-p(j)|<>6k for all j>=1, k>=1, 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. A189271, A000170, A189838, A189839, A189840, A189841

%K nonn,hard

%O 1,2

%A _Vaclav Kotesovec_, Apr 29 2011