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A146648 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1010-1111-1000 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 7, 13, 45, 61, 187, 447, 2017, 5419, 35435, 111161, 866245, 3379807, 30738337, 147143823, 1633304661 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

LINKS

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

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.1.1.1.0

.1.0.1.0.0.1.0.0

.1.1.1.1.0.1.1.0

.1.0.0.0.0.1.0.0

.0.0.1.0.0.0.0.1

.0.1.1.0.1.1.1.1

.0.0.1.0.0.1.0.1

.0.1.1.1.0.0.0.0

CROSSREFS

Sequence in context: A023286 A287685 A159305 * A219501 A267310 A153119

Adjacent sequences:  A146645 A146646 A146647 * A146649 A146650 A146651

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved

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Last modified January 22 22:16 EST 2020. Contains 331166 sequences. (Running on oeis4.)