A147488 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 11011-01110-00100 pattern in any orientation.

1, 1, 1, 1, 1, 5, 20, 49, 167, 643, 3053, 16577, 118904, 896633, 8867027, 91561000, 1224859380, 17454229913

Offset

1,6

Links

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

Example

Maximal 8 X 8 example
.0.0.0.1.1.0.1.1
.1.0.0.0.1.1.1.0
.1.1.0.0.0.1.0.1
.0.1.1.0.0.0.1.1
.1.1.0.0.0.1.1.0
.1.0.1.0.0.0.1.1
.0.1.1.1.0.0.0.1
.1.1.0.1.1.0.0.0

Crossrefs

Sequence in context: A160749 A147002 A005287 * A297569 A190094 A134481

Adjacent sequences: A147485 A147486 A147487 * A147489 A147490 A147491

Keyword

nonn

Author

R. H. Hardin

Status

approved