A146419 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1111-1000 pattern in any orientation.

1, 1, 1, 1, 1, 1, 5, 9, 24, 33, 92, 207, 751, 1987, 9135, 27247, 151575, 553091, 3687021, 16183258, 127736835, 672115551, 6393532548, 40630854716, 467493592708

Offset

1,7

Links

Table of n, a(n) for n=1..25.

Example

Maximal 8 X 8 example
.0.1.1.1.0.0.0.0
.0.0.1.0.0.0.0.1
.0.0.1.0.1.1.1.1
.0.0.1.0.0.0.0.1
.1.0.0.0.0.1.0.0
.1.1.1.1.0.1.0.0
.1.0.0.0.0.1.0.0
.0.0.0.0.1.1.1.0

Crossrefs

Sequence in context: A271543 A272256 A132354 * A365070 A162907 A165345

Adjacent sequences: A146416 A146417 A146418 * A146420 A146421 A146422

Keyword

nonn

Author

R. H. Hardin

Status

approved