A146143 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A146143

Number of n X n binary arrays symmetric under 180 degree rotation 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, 13, 51, 327, 1743, 13905, 216443, 3286293, 80038799, 2242888197, 93345565591, 4572631279405, 334861611729305

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

OFFSET

1,5

LINKS

Table of n, a(n) for n=1..16.

EXAMPLE

Maximal 8 X 8 example

.0.1.1.0.0.0.1.0

.1.1.0.0.0.1.1.1

.0.1.0.0.1.0.0.1

.0.0.1.0.1.1.1.0

.0.1.1.1.0.1.0.0

.1.0.0.1.0.0.1.0

.1.1.1.0.0.0.1.1

.0.1.0.0.0.1.1.0

CROSSREFS

Sequence in context: A332589 A022283 A135971 * A108919 A002792 A183941

Adjacent sequences: A146140 A146141 A146142 * A146144 A146145 A146146

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 27 2008

STATUS

approved