A146174 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 110-100-111 pattern in any orientation.

1, 1, 1, 1, 3, 13, 31, 79, 513, 4397, 30071, 246251, 3267201, 56899771, 1043804543, 23549434373, 739313753641, 29199724578735, 1349766896974211, 78078882718269849, 5907673396173869799

Offset

1,5

Links

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

Example

Maximal 8 X 8 example
.0.0.1.1.1.0.0.0
.0.0.0.0.1.0.0.0
.1.0.0.1.1.0.0.0
.1.0.1.0.0.1.1.1
.1.1.1.0.0.1.0.1
.0.0.0.1.1.0.0.1
.0.0.0.1.0.0.0.0
.0.0.0.1.1.1.0.0

Crossrefs

Sequence in context: A007686 A147030 A146259 * A147134 A146842 A146191

Adjacent sequences: A146171 A146172 A146173 * A146175 A146176 A146177

Keyword

nonn

Author

R. H. Hardin, Oct 27 2008

Status

approved