login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A146284 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 111-110-111 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 1, 1, 5, 9, 17, 25, 55, 133, 419, 1009, 4455, 14333, 61219, 207501, 982915, 4258653, 26235061, 130258871, 1014665059, 6176852821 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

Table of n, a(n) for n=1..26.

EXAMPLE

Maximal 9 X 9 example

.0.0.0.1.0.1.0.0.0

.0.0.0.1.1.1.0.0.0

.0.0.0.1.1.1.0.0.0

.1.1.1.0.0.0.1.1.1

.0.1.1.0.0.0.1.1.0

.1.1.1.0.0.0.1.1.1

.0.0.0.1.1.1.0.0.0

.0.0.0.1.1.1.0.0.0

.0.0.0.1.0.1.0.0.0

CROSSREFS

Sequence in context: A080335 A089109 A100449 * A175543 A200078 A190806

Adjacent sequences:  A146281 A146282 A146283 * A146285 A146286 A146287

KEYWORD

nonn

AUTHOR

R. H. Hardin

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 6 12:43 EST 2016. Contains 278781 sequences.