A146378 - OEIS

A146378

Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 0100-1111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 5, 1, 16, 5, 66, 13, 195, 31, 1006, 121, 6245, 491, 48466, 3357, 493217, 25639, 5217946, 206564, 68677904, 2153667

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OFFSET

1,9

LINKS

Table of n, a(n) for n=1..30.

EXAMPLE

Maximal 9 X 9 example

.0.0.0.0.1.0.0.0.0

.0.0.0.1.1.1.0.0.0

.0.0.1.0.1.0.1.0.0

.1.1.1.1.0.1.1.1.1

.0.0.1.0.1.0.1.0.0

.0.0.0.1.1.1.0.0.0

.0.0.0.0.1.0.0.0.0

CROSSREFS

Sequence in context: A289310 A160085 A147024 * A166086 A232101 A176249

Adjacent sequences: A146375 A146376 A146377 * A146379 A146380 A146381

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved