A147118 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1000-1000-1111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 3, 11, 27, 63, 285, 1745, 11867, 83339, 729439, 8174347, 113015753, 1872094927, 37173405545, 899575608439, 26450719284143

Offset

1,6

Links

Table of n, a(n) for n=1..20.

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.1
.0.0.0.0.0.0.0.1
.0.0.0.0.1.1.1.1
.0.0.0.1.0.0.1.0
.0.0.0.1.0.0.0.0
.0.0.0.1.1.0.0.0
.0.1.1.1.0.0.0.0

Crossrefs

Sequence in context: A147173 A147110 A372612 * A147157 A146826 A059400

Adjacent sequences: A147115 A147116 A147117 * A147119 A147120 A147121

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved