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!)
A146940 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1111-1111 pattern in any orientation. 0
1, 1, 1, 3, 5, 9, 19, 60, 189, 892, 3177, 18960, 89571, 754227, 4905159, 53337014, 466215312, 6729449504, 78188089715, 1533329125669 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
LINKS
EXAMPLE
Maximal 8 X 8 example
.1.1.0.0.1.1.0.0
.1.1.0.0.1.1.0.0
.1.1.0.0.1.1.0.0
.1.1.0.0.1.1.0.0
.0.0.1.1.0.0.1.1
.0.0.1.1.0.0.1.1
.0.0.1.1.0.0.1.1
.0.0.1.1.0.0.1.1
CROSSREFS
Sequence in context: A147470 A147010 A146912 * A146251 A281732 A066777
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 04 2008
STATUS
approved

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 May 26 22:32 EDT 2024. Contains 372847 sequences. (Running on oeis4.)