A147041 - OEIS

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A147041

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

1, 1, 1, 1, 1, 1, 1, 3, 15, 27, 43, 77, 211, 651, 2217, 7655, 29663

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

OFFSET

1,8

LINKS

Table of n, a(n) for n=1..17.

EXAMPLE

Maximal 8 X 8 example

.0.0.1.0.0.0.1.0

.1.1.1.1.0.0.1.0

.0.0.1.0.1.1.1.1

.0.0.1.0.0.0.1.0

.0.1.0.0.0.1.0.0

.1.1.1.1.0.1.0.0

.0.1.0.0.1.1.1.1

.0.1.0.0.0.1.0.0

CROSSREFS

Sequence in context: A105549 A080065 A017557 * A347536 A002259 A050848

Adjacent sequences: A147038 A147039 A147040 * A147042 A147043 A147044

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved