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!)
A146623 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1001-1111 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 1, 3, 1, 5, 1, 7, 5, 21, 13, 69, 33, 309, 131, 1529, 465, 8153, 2505, 52849, 18109, 418127, 137539, 4312045, 1253575, 52848473 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,8

LINKS

Table of n, a(n) for n=1..30.

EXAMPLE

Maximal 8 X 8 example

.0.0.1.0.0.1.0.0

.0.0.1.1.1.1.0.0

.1.1.0.0.0.0.1.1

.0.1.0.0.0.0.1.0

.0.1.0.0.0.0.1.0

.1.1.0.0.0.0.1.1

.0.0.1.1.1.1.0.0

.0.0.1.0.0.1.0.0

CROSSREFS

Sequence in context: A254938 A244149 A147410 * A197943 A318828 A318827

Adjacent sequences: A146620 A146621 A146622 * A146624 A146625 A146626

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 January 30 10:26 EST 2023. Contains 359943 sequences. (Running on oeis4.)