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A146239 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 110-111-001 pattern in any orientation. 0
1, 1, 1, 1, 9, 41, 201, 1157, 6733, 60161, 712733, 11701425, 239309475, 6797981481, 227189935315, 9296498773239, 488912114784905 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Table of n, a(n) for n=1..17.

EXAMPLE

Maximal 8 X 8 example

.0.1.1.0.0.1.1.0

.1.1.1.0.0.1.1.1

.1.0.0.0.1.0.0.1

.0.1.1.0.1.1.1.0

.0.1.1.1.0.1.1.0

.1.0.0.1.0.0.0.1

.1.1.1.0.0.1.1.1

.0.1.1.0.0.1.1.0

CROSSREFS

Sequence in context: A276780 A183916 A199311 * A083085 A147283 A171422

Adjacent sequences:  A146236 A146237 A146238 * A146240 A146241 A146242

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved

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Last modified May 26 04:43 EDT 2022. Contains 354074 sequences. (Running on oeis4.)