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A146284 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 111-110-111 pattern in any orientation. 0
1, 1, 1, 1, 1, 1, 1, 1, 5, 9, 17, 25, 55, 133, 419, 1009, 4455, 14333, 61219, 207501, 982915, 4258653, 26235061, 130258871, 1014665059, 6176852821 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

Table of n, a(n) for n=1..26.

EXAMPLE

Maximal 9 X 9 example

.0.0.0.1.0.1.0.0.0

.0.0.0.1.1.1.0.0.0

.0.0.0.1.1.1.0.0.0

.1.1.1.0.0.0.1.1.1

.0.1.1.0.0.0.1.1.0

.1.1.1.0.0.0.1.1.1

.0.0.0.1.1.1.0.0.0

.0.0.0.1.1.1.0.0.0

.0.0.0.1.0.1.0.0.0

CROSSREFS

Sequence in context: A080335 A089109 A100449 * A175543 A200078 A190806

Adjacent sequences:  A146281 A146282 A146283 * A146285 A146286 A146287

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved

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Last modified September 1 17:49 EDT 2014. Contains 246309 sequences.