A147137 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1001-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 3, 13, 33, 61, 123, 351, 1083, 3363, 12745, 54981, 257267, 1349181, 7264663, 42437683, 269731743

Offset

1,7

Links

Table of n, a(n) for n=1..21.

Example

Maximal 8 X 8 example
.0.0.0.0.1.1.1.0
.1.1.1.1.0.0.1.0
.1.0.0.1.0.0.1.0
.1.0.0.0.0.1.1.0
.0.1.1.0.0.0.0.1
.0.1.0.0.1.0.0.1
.0.1.0.0.1.1.1.1
.0.1.1.1.0.0.0.0

Crossrefs

Sequence in context: A061938 A168375 A032586 * A146230 A166805 A252979

Adjacent sequences: A147134 A147135 A147136 * A147138 A147139 A147140

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved