A146039 - OEIS

A146039

Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 2X4 tee 1,1 1,2 1,3 2,3 1,4 in any orientation.

1, 1, 1, 1, 9, 13, 45, 103, 3815, 10121, 444625, 1564307, 156192449, 708716121, 155685558737, 926098788583, 445436128809681, 3444294518750191, 3885959472155218673, 39161185591962243237, 94947827514803095335545

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

OFFSET

1,5

LINKS

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

EXAMPLE

Maximal 8 X 8 example

.1.0.0.0.0.0.0.1

.1.1.0.0.0.0.1.1

.1.0.0.0.0.0.0.1

.0.0.1.0.0.1.0.0

.0.1.1.0.0.1.1.0

.0.0.1.0.0.1.0.0

CROSSREFS

Sequence in context: A068984 A146016 A146128 * A287005 A270234 A270718

Adjacent sequences: A146036 A146037 A146038 * A146040 A146041 A146042

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 26 2008

STATUS

approved