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A146678 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-0111-1100 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 1, 1, 4, 7, 14, 21, 42, 97, 337, 907, 3367, 9291, 36318, 129686, 674043, 2983615, 17944470, 88292506, 606666014, 3595901269, 30553144868, 219341547026 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

Table of n, a(n) for n=1..28.

EXAMPLE

Maximal 9 X 9 example

.0.0.0.0.1.1.0.0.0

.0.0.1.1.1.0.0.0.0

.0.1.0.0.1.1.0.0.0

.0.1.0.0.0.0.1.0.1

.1.1.1.0.0.0.1.1.1

.1.0.1.0.0.0.0.1.0

.0.0.0.1.1.0.0.1.0

.0.0.0.0.1.1.1.0.0

.0.0.0.1.1.0.0.0.0

CROSSREFS

Sequence in context: A147372 A201272 A147440 * A146417 A008370 A291877

Adjacent sequences:  A146675 A146676 A146677 * A146679 A146680 A146681

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved

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Last modified July 24 03:29 EDT 2021. Contains 346273 sequences. (Running on oeis4.)