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A146225 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 1100-1111 pattern in any orientation. 0
1, 1, 1, 1, 9, 13, 39, 69, 2575, 6405, 191203, 599559, 31751065, 124920743, 19072164165, 96207487051, 23729375699967, 150729249130871, 86943333060607105, 701895334984042253, 791712727158897187729 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

LINKS

Table of n, a(n) for n=1..21.

EXAMPLE

Maximal 8 X 8 example

.1.1.0.0.0.0.1.1

.1.1.0.0.0.0.1.1

.1.0.0.0.0.0.0.1

.1.0.0.0.0.0.0.1

.0.0.1.0.0.1.0.0

.0.0.1.0.0.1.0.0

.0.1.1.0.0.1.1.0

.0.1.1.0.0.1.1.0

CROSSREFS

Sequence in context: A147352 A147391 A241677 * A219257 A200537 A160118

Adjacent sequences:  A146222 A146223 A146224 * A146226 A146227 A146228

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved

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Last modified November 30 05:12 EST 2021. Contains 349419 sequences. (Running on oeis4.)