A146636 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1010-1111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 49, 49, 309, 309, 4193, 4193, 83267, 83267, 2435243, 2435243, 97883893, 97883893

Offset

1,9

Links

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

Example

Maximal 9 X 9 example
.0.0.0.0.0.0.0.0.0
.0.0.1.0.0.0.1.0.0
.1.1.1.1.0.1.1.1.1
.0.1.0.1.0.1.0.1.0
.0.0.0.0.0.0.0.0.0
.0.1.0.1.0.1.0.1.0
.1.1.1.1.0.1.1.1.1
.0.0.1.0.0.0.1.0.0
.0.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A146732 A146588 A146628 * A146833 A146700 A146708

Adjacent sequences: A146633 A146634 A146635 * A146637 A146638 A146639

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved