A146064 Number of n X n binary arrays symmetric under horizontal reflection 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, 49, 91, 755, 1733, 17237, 43939, 2178205, 7075949, 921596877, 3869156215, 535678119399, 2790029976011, 707504525942961, 4543722915142743, 2950922408069540377, 23782316720866894839, 30573780517964151258947

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.1.0.0.0.0.0.0.1
.1.1.1.0.0.1.1.1
.0.0.1.0.0.1.0.0
.0.0.0.0.0.0.0.0
.1.0.0.0.0.0.0.1
.1.1.1.0.0.1.1.1
.0.0.1.0.0.1.0.0

Crossrefs

Sequence in context: A020158 A084632 A020176 * A224905 A224846 A260469

Adjacent sequences: A146061 A146062 A146063 * A146065 A146066 A146067

Keyword

nonn

Author

R. H. Hardin, Oct 26 2008

Status

approved