A146873 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1110-0100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 49, 49, 129, 129, 2097, 2097, 70513, 70513, 1502401, 1502401, 23706401, 23706401

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.1.0.1.0.0.0
.0.1.0.1.0.1.0.1.0
.0.1.1.1.0.1.1.1.0
.0.1.0.0.0.0.0.1.0
.0.0.0.0.0.0.0.0.0
.0.1.0.0.0.0.0.1.0
.0.1.1.1.0.1.1.1.0
.0.1.0.1.0.1.0.1.0
.0.0.0.1.0.1.0.0.0

Crossrefs

Sequence in context: A333152 A040273 A022351 * A146793 A146801 A147203

Adjacent sequences: A146870 A146871 A146872 * A146874 A146875 A146876

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved