A189871 - OEIS

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

%S 1,0,0,2,10,0,8,24,72,116,384,1660,7344,24364,130408,743360,4242704,

%T 27018788,190618152,1431986780,11053915716

%N Number of ways to place n nonattacking composite pieces queen + leaper[3,5] on an n X n chessboard.

%C a(n) is also number of permutations p of 1,2,...,n satisfying |p(i+3)-p(i)|<>5 AND |p(j+5)-p(j)|<>3 AND |p(m+k)-p(m)|<>k for all i>=1, j>=1, m>=1, k>=1, i+3<=n, j+5<=n, m+k<=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. A051223, A189866, A189869, A189569, A189870

%K nonn,hard

%O 1,4

%A _Vaclav Kotesovec_, Apr 29 2011