A146625 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1001-1111 pattern in any orientation.

1, 1, 1, 1, 9, 17, 43, 177, 951, 5185, 35811, 267203, 2640609, 29564643, 461890027, 7371309815, 158387025739, 3708738153141

Offset

1,5

Links

Table of n, a(n) for n=1..18.

Example

Maximal 8 X 8 example
.0.0.1.1.0.0.0.0
.1.1.0.1.0.0.0.0
.1.0.0.1.0.0.0.0
.1.0.1.1.0.0.1.1
.1.1.0.0.1.1.0.1
.0.0.0.0.1.0.0.1
.0.0.0.0.1.0.1.1
.0.0.0.0.1.1.0.0

Crossrefs

Sequence in context: A245542 A186298 A147245 * A318755 A146576 A147138

Adjacent sequences: A146622 A146623 A146624 * A146626 A146627 A146628

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved