A146580 - OEIS

A146580

Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 0100-1100-0111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 17, 17, 57, 57, 457, 457, 7575, 7575, 206575, 206575, 7284891, 7284891, 429058537, 429058537, 43146239725, 43146239725

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

OFFSET

1,9

LINKS

Table of n, a(n) for n=1..24.

EXAMPLE

Maximal 9 X 9 example

.1.1.1.0.0.0.1.1.1

.0.0.1.1.0.1.1.0.0

.0.0.1.0.0.0.1.0.0

.0.0.0.0.0.0.0.0.0

.0.0.1.0.0.0.1.0.0

.0.0.1.1.0.1.1.0.0

.1.1.1.0.0.0.1.1.1

CROSSREFS

Sequence in context: A146572 A147211 A147241 * A146455 A146048 A146809

Adjacent sequences: A146577 A146578 A146579 * A146581 A146582 A146583

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 04 2008

STATUS

approved