A146670 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-0111-0110 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 9, 19, 33, 71, 215, 791, 3245, 13621, 57411, 277797, 1527109, 9994857, 71286549, 571498723

Offset

1,8

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.1.1.0.0
.0.0.1.1.1.0.0.0
.0.1.0.1.1.0.0.1
.0.1.1.0.0.1.1.1
.1.1.1.0.0.1.1.0
.1.0.0.1.1.0.1.0
.0.0.0.1.1.1.0.0
.0.0.1.1.0.0.0.0

Crossrefs

Sequence in context: A146702 A146734 A146614 * A146409 A147111 A146401

Adjacent sequences: A146667 A146668 A146669 * A146671 A146672 A146673

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved