A146150 Number of n X n binary arrays symmetric under 90 degree rotation 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, 11, 21, 45, 147, 455, 1443, 6641, 31711, 178915, 1031021, 7211761, 51418401, 452868901, 4229697689, 48322007005, 572003003167

Offset

1,7

Links

Table of n, a(n) for n=1..22.

Example

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

Crossrefs

Sequence in context: A333356 A127624 A097616 * A244069 A058489 A278780

Adjacent sequences: A146147 A146148 A146149 * A146151 A146152 A146153

Keyword

nonn

Author

R. H. Hardin, Oct 27 2008

Status

approved