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A146268 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 110-111-110 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 2, 5, 10, 17, 30, 77, 254, 873, 2865, 9282, 36476, 176379, 950600, 5334620, 30998066, 200015663, 1516056134, 12927161092, 120013319909, 1186872290095, 12868902178120, 156796551881590 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

LINKS

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

EXAMPLE

Maximal 8 X 8 example

.0.0.0.1.1.1.0.0

.0.0.0.1.1.1.0.0

.0.0.0.0.1.0.1.1

.1.1.0.0.0.1.1.1

.1.1.1.0.0.0.1.1

.1.1.0.1.0.0.0.0

.0.0.1.1.1.0.0.0

.0.0.1.1.1.0.0.0

CROSSREFS

Sequence in context: A172167 A173060 A173520 * A038358 A107482 A227363

Adjacent sequences:  A146265 A146266 A146267 * A146269 A146270 A146271

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved

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Last modified June 20 06:56 EDT 2021. Contains 345157 sequences. (Running on oeis4.)