login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A189853 Number of ways to place n nonattacking composite pieces rook + rider[1,6] on an n X n chessboard. 4

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

%S 1,2,6,24,120,720,2640,13596,87768,680274,6090756,61678252,482005340,

%T 4454053680,46705656280,549750105234

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

%C a(n) is also number of permutations p of 1,2,...,n satisfying |p(i+k)-p(i)|<>6k AND |p(j+6k)-p(j)|<>k for all i>=1, j>=1, k>=1, i+k<=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, A189837, A189850, A189851, A189852

%K nonn,hard

%O 1,2

%A _Vaclav Kotesovec_, Apr 29 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 20 05:30 EDT 2024. Contains 374441 sequences. (Running on oeis4.)