login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A147287 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1100-0111-0001-0001 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 1, 1, 25, 41, 113, 265, 1045, 2597, 10607, 34895, 213407, 913033, 6860785, 33581603 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

Table of n, a(n) for n=1..20.

EXAMPLE

Maximal 9 X 9 example

.1.0.0.0.0.0.0.1.1

.1.1.0.0.0.1.1.1.0

.0.1.0.0.0.1.0.0.0

.0.1.1.1.0.1.0.0.0

.0.0.0.0.0.0.0.0.0

.0.0.0.1.0.1.1.1.0

.0.0.0.1.0.0.0.1.0

.0.1.1.1.0.0.0.1.1

.1.1.0.0.0.0.0.0.1

CROSSREFS

Sequence in context: A309623 A242074 A195564 * A240758 A031331 A236838

Adjacent sequences:  A147284 A147285 A147286 * A147288 A147289 A147290

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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 4 12:51 EST 2021. Contains 349523 sequences. (Running on oeis4.)