A146128 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 3X2 zee 1,1 1,2 1,3 2,3 2,4 in any orientation.

1, 1, 1, 1, 9, 13, 45, 103, 3361, 8833, 372663, 1287127, 106100985, 471171193, 109709730093, 638573372655, 304442910936313, 2309148561615411, 2461266528050264151, 24325578567487185537, 57639766702959393452219

Offset

1,5

Links

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

Example

Maximal 8 X 8 example
.0.1.0.0.0.0.1.0
.1.1.0.0.0.0.1.1
.1.0.0.0.0.0.0.1
.1.0.0.0.0.0.0.1
.0.0.1.0.0.1.0.0
.0.0.1.0.0.1.0.0
.0.1.1.0.0.1.1.0
.0.1.0.0.0.0.1.0

Crossrefs

Sequence in context: A160117 A068984 A146016 * A146039 A287005 A270234

Adjacent sequences: A146125 A146126 A146127 * A146129 A146130 A146131

Keyword

nonn

Author

R. H. Hardin, Oct 27 2008

Status

approved