A147260 - OEIS

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A147260

Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 0001-1101-0111 pattern in any orientation.

1, 1, 1, 1, 5, 17, 49, 213, 1189, 5181, 36191, 306061, 3589171

(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

.0.1.1.1.0.0.0.0

.1.1.0.1.0.0.0.0

.0.0.0.1.0.0.0.1

.1.1.1.0.1.1.0.1

.1.0.1.1.0.1.1.1

.1.0.0.0.1.0.0.0

.0.0.0.0.1.0.1.1

.0.0.0.0.1.1.1.0

CROSSREFS

Sequence in context: A176953 A082753 A000337 * A273688 A146045 A086866

Adjacent sequences: A147257 A147258 A147259 * A147261 A147262 A147263

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved