A147189 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

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 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A147189

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 11000-01110-00011 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 3, 5, 11, 19, 53, 119, 315, 741, 2791, 8507, 37441, 131241, 690373, 2947311, 17685311, 87080583, 622517947, 3695889011, 31549600531

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,9

LINKS

Table of n, a(n) for n=1..27.

EXAMPLE

Maximal 9 X 9 example

.0.0.0.0.0.0.1.1.0

.0.0.0.0.1.1.1.0.1

.0.0.0.1.1.0.0.1.1

.0.0.1.0.0.0.0.1.0

.0.1.1.0.0.0.1.1.0

.0.1.0.0.0.0.1.0.0

.1.1.0.0.1.1.0.0.0

.1.0.1.1.1.0.0.0.0

.0.1.1.0.0.0.0.0.0

CROSSREFS

Sequence in context: A281380 A117272 A243616 * A118744 A092672 A061068

Adjacent sequences: A147186 A147187 A147188 * A147190 A147191 A147192

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved