A145944 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected in a 3X2 elbow 1,1 1,2 1,3 2,3 in any orientation.

1, 1, 1, 1, 13, 19, 595, 1473, 41647, 139371, 13954303, 64086157, 18839470495, 119460750005, 78516712094765, 679135834059151, 1132864641733411477, 13390989972487068017, 60598468634533341708705, 981938713996881194950713

Offset

1,5

Links

Table of n, a(n) for n=1..20.

Example

Maximal 8 X 8 example
.1.1.1.0.0.1.1.1
.1.0.0.0.0.0.0.1
.0.1.1.0.0.1.1.0
.1.0.1.0.0.1.0.1
.1.0.1.0.0.1.0.1
.1.1.0.0.0.0.1.1
.0.0.1.0.0.1.0.0
.1.1.1.0.0.1.1.1

Crossrefs

Sequence in context: A088187 A146047 A343034 * A355964 A330425 A335971

Adjacent sequences: A145941 A145942 A145943 * A145945 A145946 A145947

Keyword

nonn

Author

R. H. Hardin, Oct 25 2008

Status

approved