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A146843 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1001-1111-1000 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 1, 1, 3, 9, 19, 33, 61, 167, 557, 1931, 7517, 29489, 124159, 584129, 3130749, 18534977 (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

.0.0.0.1.0.0.1.0.0

.0.0.0.1.1.1.1.0.0

.0.0.0.1.0.0.0.1.1

.1.1.1.0.0.0.0.1.0

.0.1.0.0.0.0.0.1.0

.0.1.0.0.0.0.1.1.1

.1.1.0.0.0.1.0.0.0

.0.0.1.1.1.1.0.0.0

.0.0.1.0.0.1.0.0.0

CROSSREFS

Sequence in context: A147055 A146638 A147135 * A146630 A146710 A146803

Adjacent sequences:  A146840 A146841 A146842 * A146844 A146845 A146846

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved

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Last modified November 27 09:19 EST 2021. Contains 349365 sequences. (Running on oeis4.)