The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A235457 Number of non-equivalent (mod D_4) ways to arrange 6 points on an n X n square grid so that no three points are collinear. 6

%I #10 Nov 16 2016 15:51:45

%S 1,142,4699,77970,672506,4338248,21167201,85351595,294664274,

%T 911848844,2528561187,6501165477

%N Number of non-equivalent (mod D_4) ways to arrange 6 points on an n X n square grid so that no three points are collinear.

%C Column 6 of A235453.

%C Without the restriction "non-equivalent (mod D_4)" the numbers are given by A194191, n >= 3.

%e There is a(3) = 1 way to place 6 points (X) on a 3 X 3 grid (without rotations and reflections):

%e . X X

%e X . X

%e X X .

%Y Cf. A235453, A194191, A235454 (3 points), A235455 (4 points), A235456 (5 points), A235458 (7 points).

%K nonn,more

%O 3,2

%A _Heinrich Ludwig_, Jan 12 2014

%E a(13), a(14) from _Heinrich Ludwig_, Nov 16 2016

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 June 17 00:51 EDT 2024. Contains 373432 sequences. (Running on oeis4.)