A147233 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1101-0111-0001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 65, 65, 377, 377, 4203, 4203, 88657, 88657, 2446623, 2446623, 84129749, 84129749

Offset

1,9

Links

Table of n, a(n) for n=1..22.

Example

Maximal 9 X 9 example
.0.0.0.0.0.0.0.0.0
.1.0.0.0.0.0.0.0.1
.1.1.1.0.0.0.1.1.1
.1.0.1.1.0.1.1.0.1
.0.0.0.0.0.0.0.0.0
.1.0.1.1.0.1.1.0.1
.1.1.1.0.0.0.1.1.1
.1.0.0.0.0.0.0.0.1
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A146455 A146048 A146809 * A146817 A146660 A070852

Adjacent sequences: A147230 A147231 A147232 * A147234 A147235 A147236

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved