A147169 - OEIS

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A147169

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1101-0111 pattern in any orientation.

1, 1, 1, 1, 9, 21, 55, 201, 1193, 6291, 45811, 376085, 4555905

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

OFFSET

1,5

LINKS

Table of n, a(n) for n=1..13.

EXAMPLE

Maximal 8 X 8 example

.0.1.1.0.0.1.1.0

.0.1.0.0.0.0.1.1

.0.1.1.0.0.0.0.1

.0.0.1.1.0.0.1.1

.1.1.0.0.1.1.0.0

.1.0.0.0.0.1.1.0

.1.1.0.0.0.0.1.0

.0.1.1.0.0.1.1.0

CROSSREFS

Sequence in context: A134717 A216980 A372664 * A216167 A246327 A320896

Adjacent sequences: A147166 A147167 A147168 * A147170 A147171 A147172

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved