A147030 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 0100-0100-1111-0010 pattern in any orientation.

1, 1, 1, 1, 1, 3, 13, 31, 77, 387, 2257, 17627, 156913, 1449769, 17078273, 269362403, 5270658519, 128747962057, 3752690933565, 128409913359645, 5451255918471683

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
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.1.0
.0.0.0.0.1.1.1.0
.0.0.0.1.0.0.1.1
.0.0.0.1.0.0.1.0
.0.0.1.1.1.1.0.0
.0.0.0.0.1.0.0.0

Crossrefs

Sequence in context: A067980 A164569 A007686 * A146259 A146174 A147134

Adjacent sequences: A147027 A147028 A147029 * A147031 A147032 A147033

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved