A146609 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1000-1111-0001 pattern in any orientation.

1, 1, 1, 1, 5, 13, 31, 93, 435, 2055, 12617, 84101, 749259, 7832803, 101765203, 1516307327, 27862176903, 604272411455

Offset

1,5

Links

Table of n, a(n) for n=1..18.

Example

Maximal 8 X 8 example
.0.0.0.1.0.0.1.1
.1.1.1.1.0.0.1.0
.1.0.0.0.0.0.1.0
.0.0.0.0.0.1.1.0
.0.1.1.0.0.0.0.0
.0.1.0.0.0.0.0.1
.0.1.0.0.1.1.1.1
.1.1.0.0.1.0.0.0

Crossrefs

Sequence in context: A097969 A082280 A007708 * A121129 A051402 A147022

Adjacent sequences: A146606 A146607 A146608 * A146610 A146611 A146612

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved