A146137 - OEIS

A146137

Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 5-point barb 1,1 1,2 2,2 2,3 3,2 in any orientation.

1, 1, 1, 1, 1, 1, 149, 307, 3283, 9637, 237685, 792401, 149008323, 690862749, 219427051049, 1350088886833, 717485827831517, 5812692511149509, 9087725403509413361, 98388300257852844757, 382960435361198474272451

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,7

LINKS

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

EXAMPLE

Maximal 8 X 8 example

.0.1.0.0.0.0.1.0

.1.1.1.0.0.1.1.1

.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

.0.1.0.0.0.0.1.0

CROSSREFS

Sequence in context: A131573 A346891 A244661 * A071331 A095842 A142359

Adjacent sequences: A146134 A146135 A146136 * A146138 A146139 A146140

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 27 2008

STATUS

approved