A146474 - OEIS

A146474

Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1110-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 3, 9, 9, 23, 23, 85, 85, 375, 375, 2149, 2149, 15299, 15299, 129877, 129877, 1353943, 1353943, 17475557, 17475557

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OFFSET

1,11

LINKS

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

EXAMPLE

Maximal 11 X 11 example

.0.0.0.1.0.0.0.1.0.0.0

.0.0.0.1.1.0.1.1.0.0.0

.1.1.1.0.1.0.1.0.1.1.1

.0.1.1.1.0.0.0.1.1.1.0

.0.0.0.0.0.0.0.0.0.0.0

.0.1.1.1.0.0.0.1.1.1.0

.1.1.1.0.1.0.1.0.1.1.1

.0.0.0.1.1.0.1.1.0.0.0

.0.0.0.1.0.0.0.1.0.0.0

CROSSREFS

Sequence in context: A146663 A146394 A147510 * A145957 A214439 A287479

Adjacent sequences: A146471 A146472 A146473 * A146475 A146476 A146477

KEYWORD

nonn

AUTHOR

R. H. Hardin

STATUS

approved