A146819 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1110-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 9, 19, 39, 117, 351, 957, 3341, 15997, 83175, 424759, 2415699, 15982837, 113541201, 873618675

Offset

1,8

Links

Table of n, a(n) for n=1..22.

Example

Maximal 8 X 8 example
.0.1.1.1.0.0.0.0
.1.0.1.1.1.0.0.0
.1.1.0.0.1.0.0.0
.1.1.0.0.0.1.1.0
.0.1.1.0.0.0.1.1
.0.0.0.1.0.0.1.1
.0.0.0.1.1.1.0.1
.0.0.0.0.1.1.1.0

Crossrefs

Sequence in context: A135117 A038163 A327381 * A147213 A146441 A147341

Adjacent sequences: A146816 A146817 A146818 * A146820 A146821 A146822

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved