A146069 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 5-point zee 1,1 2,1 2,2 2,3 3,3 in any orientation.

1, 1, 1, 1, 1, 1, 9, 21, 35, 101, 287, 859, 3329, 15189, 75035, 399377, 2204921, 14787995, 102936591, 860535039, 7743744003, 81593423043, 911784626279

Offset

1,7

Links

Table of n, a(n) for n=1..23.

Example

Maximal 8 X 8 example
.1.0.0.0.0.0.1.1
.1.1.1.0.0.0.1.0
.0.0.1.0.0.1.1.0
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.0.1.1.0.0.1.0.0
.0.1.0.0.0.1.1.1
.1.1.0.0.0.0.0.1

Crossrefs

Sequence in context: A043112 A043892 A332019 * A140673 A186294 A059993

Adjacent sequences: A146066 A146067 A146068 * A146070 A146071 A146072

Keyword

nonn

Author

R. H. Hardin, Oct 26 2008

Status

approved