A146930 Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1001-1111-1001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 7, 14, 17, 38

Offset

1,10

Links

Table of n, a(n) for n=1..19.

Example

Maximal 10 X 10 example
.0.0.0.1.0.0.1.0.0.0
.0.0.0.1.1.1.1.0.0.0
.0.0.0.1.0.0.1.0.0.0
.1.1.1.0.0.0.0.1.1.1
.0.1.0.0.0.0.0.0.1.0
.0.1.0.0.0.0.0.0.1.0
.1.1.1.0.0.0.0.1.1.1
.0.0.0.1.0.0.1.0.0.0
.0.0.0.1.1.1.1.0.0.0
.0.0.0.1.0.0.1.0.0.0

Crossrefs

Sequence in context: A369986 A035657 A018053 * A333524 A319728 A241152

Adjacent sequences: A146927 A146928 A146929 * A146931 A146932 A146933

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved