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A146851 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111-0001 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 1, 1, 5, 13, 25, 45, 129, 391, 1245, 4737, 21985, 95961, 496289, 2673135, 16997063, 114065803 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

Table of n, a(n) for n=1..22.

EXAMPLE

Maximal 9 X 9 example

.0.0.0.0.0.1.1.0.0

.0.0.0.1.1.1.1.0.0

.0.0.0.1.0.0.0.1.1

.0.1.1.0.0.0.0.1.1

.0.1.0.0.0.0.0.1.0

.1.1.0.0.0.0.1.1.0

.1.1.0.0.0.1.0.0.0

.0.0.1.1.1.1.0.0.0

.0.0.1.1.0.0.0.0.0

CROSSREFS

Sequence in context: A196069 A147182 A146175 * A146260 A147166 A146192

Adjacent sequences:  A146848 A146849 A146850 * A146852 A146853 A146854

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved

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Last modified December 5 10:11 EST 2021. Contains 349543 sequences. (Running on oeis4.)