A146780 - OEIS

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A146780

Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 0010-1010-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 5, 17, 17, 43, 43, 145, 145, 633, 633

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,13

LINKS

Table of n, a(n) for n=1..22.

EXAMPLE

Maximal 13 X 13 example

.0.0.0.0.0.1.0.1.0.0.0.0.0

.0.0.0.1.1.1.0.1.1.1.0.0.0

.0.0.0.0.0.1.0.1.0.0.0.0.0

.0.1.0.0.1.1.0.1.1.0.0.1.0

.0.1.0.1.0.0.0.0.0.1.0.1.0

.1.1.1.1.0.0.0.0.0.1.1.1.1

.0.0.0.0.0.0.0.0.0.0.0.0.0

.1.1.1.1.0.0.0.0.0.1.1.1.1

.0.1.0.1.0.0.0.0.0.1.0.1.0

.0.1.0.0.1.1.0.1.1.0.0.1.0

.0.0.0.0.0.1.0.1.0.0.0.0.0

.0.0.0.1.1.1.0.1.1.1.0.0.0

.0.0.0.0.0.1.0.1.0.0.0.0.0

CROSSREFS

Sequence in context: A147037 A146796 A146836 * A146860 A146185 A147399

Adjacent sequences: A146777 A146778 A146779 * A146781 A146782 A146783

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved