A146850 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1100-1111-0001 pattern in any orientation.

1, 1, 1, 1, 1, 5, 17, 37, 137, 741, 5145, 37997, 337079, 3889419, 55427643, 967896983, 20644031605, 543669795557, 17692139622867, 706505935324823

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
.0.0.0.0.0.0.0.0
.0.0.0.0.1.0.0.0
.0.0.0.0.1.1.1.1
.0.0.1.1.0.0.1.1
.0.0.0.1.0.0.0.0
.0.0.0.1.1.0.0.0
.0.0.0.1.1.0.0.0

Crossrefs

Sequence in context: A146280 A282511 A147181 * A146428 A146235 A087728

Adjacent sequences: A146847 A146848 A146849 * A146851 A146852 A146853

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved