A147474 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1100-1111-0100-0100 pattern in any orientation.

1, 1, 1, 1, 1, 3, 11, 35, 119, 483, 1553, 7807, 47813, 363745, 2696139

Offset

1,6

Links

Table of n, a(n) for n=1..15.

Example

Maximal 8 X 8 example
.0.0.1.0.0.0.1.1
.0.0.1.0.1.1.1.1
.1.1.1.1.0.0.1.0
.0.0.1.1.0.0.1.0
.0.1.0.0.1.1.0.0
.0.1.0.0.1.1.1.1
.1.1.1.1.0.1.0.0
.1.1.0.0.0.1.0.0

Crossrefs

Sequence in context: A259400 A320087 A014335 * A247417 A222286 A119143

Adjacent sequences: A147471 A147472 A147473 * A147475 A147476 A147477

Keyword

nonn

Author

R. H. Hardin

Status

approved