A146622 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1001-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 5, 11, 17, 31, 67, 255, 681, 2579, 7475, 30835, 113699, 646479, 2916183, 18956135, 100069407, 770834039, 4965697461, 47266430445, 367691554109, 4176001047493, 38902939183671

Offset

1,8

Links

Table of n, a(n) for n=1..29.

Example

Maximal 8 X 8 example
.0.0.1.0.0.1.0.0
.0.0.1.1.1.1.0.0
.1.1.0.0.0.0.1.1
.0.1.0.0.0.0.1.0
.0.1.0.0.0.0.1.0
.1.1.0.0.0.0.1.1
.0.0.1.1.1.1.0.0
.0.0.1.0.0.1.0.0

Crossrefs

Sequence in context: A085918 A267094 A336372 * A124179 A124173 A091610

Adjacent sequences: A146619 A146620 A146621 * A146623 A146624 A146625

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved