A146874 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1110-0100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 5, 17, 37, 81, 581, 4553, 28101, 163497, 1904517, 29561545, 451624245, 6956479641, 156904159893, 4856658148681, 169058959345685, 6417340281818617

Offset

1,6

Links

Table of n, a(n) for n=1..21.

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.0.0.0.1.1.1
.0.0.0.0.0.0.1.0
.0.0.0.0.1.1.1.0
.0.0.0.1.0.0.0.0
.0.1.0.1.0.0.0.0
.0.1.1.1.0.0.0.0
.0.1.0.0.0.0.0.0

Crossrefs

Sequence in context: A107199 A048209 A181423 * A145012 A360204 A147204

Adjacent sequences: A146871 A146872 A146873 * A146875 A146876 A146877

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved