A146146 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in an em 1,1 1,2 2,2 2,3 3,3 in any orientation.

1, 1, 1, 1, 1, 1, 5, 5, 19, 19, 97, 97, 863, 863, 18767, 18767, 490889, 490889, 19713443, 19713443, 1413873475, 1413873475, 167866752937, 167866752937, 30662833126025, 30662833126025

Offset

1,7

Links

Table of n, a(n) for n=1..26.

Example

Maximal 8 X 8 example
.1.0.0.0.0.0.0.1
.1.1.0.0.0.0.1.1
.0.1.1.0.0.1.1.0
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.0.1.1.0.0.1.1.0
.1.1.0.0.0.0.1.1
.1.0.0.0.0.0.0.1

Crossrefs

Sequence in context: A147093 A147101 A147141 * A145937 A246983 A305514

Adjacent sequences: A146143 A146144 A146145 * A146147 A146148 A146149

Keyword

nonn

Author

R. H. Hardin, Oct 27 2008

Status

approved