A146781 - OEIS

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A146781

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

1, 1, 1, 1, 1, 1, 5, 17, 37, 69, 119, 413, 1361, 4953, 21841, 100255, 486625, 2729263, 14571959, 98507721, 677047259

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

OFFSET

1,7

LINKS

Table of n, a(n) for n=1..21.

EXAMPLE

Maximal 8 X 8 example

.0.0.0.0.0.1.1.0

.1.1.1.1.0.0.1.0

.1.0.1.0.1.1.1.0

.0.0.1.0.0.0.1.0

.0.1.0.0.0.1.0.0

.0.1.1.1.0.1.0.1

.0.1.0.0.1.1.1.1

.0.1.1.0.0.0.0.0

CROSSREFS

Sequence in context: A273250 A053755 A162373 * A338277 A348228 A107199

Adjacent sequences: A146778 A146779 A146780 * A146782 A146783 A146784

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved