A147129 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1000-1111-1000 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 7, 25, 45, 79, 171, 569, 1763, 6023, 22593, 106741, 481403, 2734225, 13695379, 86954465

Offset

1,8

Links

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

Example

Maximal 8 X 8 example
.1.0.0.0.1.1.1.1
.1.0.0.0.0.1.0.0
.1.1.1.1.0.1.0.0
.1.0.0.0.0.1.0.0
.0.0.1.0.0.0.0.1
.0.0.1.0.1.1.1.1
.0.0.1.0.0.0.0.1
.1.1.1.1.0.0.0.1

Crossrefs

Sequence in context: A119617 A102027 A031294 * A173825 A269589 A278874

Adjacent sequences: A147126 A147127 A147128 * A147130 A147131 A147132

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved