A145999 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 3X3 plus 2,1 2,2 2,3 1,2 3,2.

1, 1, 2, 1, 2, 1, 7, 2, 23, 5, 132, 12, 836, 51, 8563, 317, 115954, 2654, 2274857, 30351, 60964251, 489559, 2304941344, 11104536, 120886008663, 350752586, 8909697213591, 15493779226, 915528841065256, 954798521885

Offset

1,3

Links

Table of n, a(n) for n=1..30.

Example

Maximal 8 X 8 example
.0.1.0.0.0.0.1.0
.1.1.1.0.0.1.1.1
.0.1.0.0.0.0.1.0
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.0.1.0.0.0.0.1.0
.1.1.1.0.0.1.1.1
.0.1.0.0.0.0.1.0

Crossrefs

Sequence in context: A046749 A016543 A300585 * A198316 A011128 A245595

Adjacent sequences: A145996 A145997 A145998 * A146000 A146001 A146002

Keyword

nonn

Author

R. H. Hardin, Oct 26 2008

Status

approved