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!)
A146143 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 5-point barb 1,1 1,2 2,2 2,3 3,2 in any orientation. 0

%I #3 Mar 31 2012 12:35:09

%S 1,1,1,1,13,51,327,1743,13905,216443,3286293,80038799,2242888197,

%T 93345565591,4572631279405,334861611729305

%N Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 5-point barb 1,1 1,2 2,2 2,3 3,2 in any orientation.

%e Maximal 8 X 8 example

%e .0.1.1.0.0.0.1.0

%e .1.1.0.0.0.1.1.1

%e .0.1.0.0.1.0.0.1

%e .0.0.1.0.1.1.1.0

%e .0.1.1.1.0.1.0.0

%e .1.0.0.1.0.0.1.0

%e .1.1.1.0.0.0.1.1

%e .0.1.0.0.0.1.1.0

%K nonn

%O 1,5

%A _R. H. Hardin_, Oct 27 2008

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 April 25 08:27 EDT 2024. Contains 371964 sequences. (Running on oeis4.)