A147169 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1101-0111 pattern in any orientation.

1, 1, 1, 1, 9, 21, 55, 201, 1193, 6291, 45811, 376085, 4555905

Offset

1,5

Links

Table of n, a(n) for n=1..13.

Example

Maximal 8 X 8 example
.0.1.1.0.0.1.1.0
.0.1.0.0.0.0.1.1
.0.1.1.0.0.0.0.1
.0.0.1.1.0.0.1.1
.1.1.0.0.1.1.0.0
.1.0.0.0.0.1.1.0
.1.1.0.0.0.0.1.0
.0.1.1.0.0.1.1.0

Crossrefs

Sequence in context: A134717 A216980 A372664 * A216167 A246327 A320896

Adjacent sequences: A147166 A147167 A147168 * A147170 A147171 A147172

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved