A147375 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 0111-1100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 5, 21, 61, 266, 891, 3074, 18035, 122510, 915879, 8736750, 97430523, 1219777035, 17287269221

Offset

1,6

Links

Table of n, a(n) for n=1..18.

Example

Maximal 8 X 8 example
.1.1.1.0.0.0.1.0
.0.0.1.1.0.1.1.1
.1.1.1.0.0.1.0.1
.0.0.0.0.0.1.0.1
.1.0.1.0.0.0.0.0
.1.0.1.0.0.1.1.1
.1.1.1.0.1.1.0.0
.0.1.0.0.0.1.1.1

Crossrefs

Sequence in context: A287617 A354551 A143567 * A351934 A356328 A147216

Adjacent sequences: A147372 A147373 A147374 * A147376 A147377 A147378

Keyword

nonn

Author

R. H. Hardin

Status

approved