A146813 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1010-1111 pattern in any orientation.

1, 1, 1, 1, 1, 1, 3, 17, 37, 69, 167, 487, 1595, 5107, 22241, 105661, 549863, 3071095, 17729121, 112871021, 819713685

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.0.0.0.1.1.1.1.0
.1.0.0.1.0.1.0.0
.1.1.0.1.0.0.0.0
.1.0.0.0.0.1.1.1
.1.1.1.0.0.0.0.1
.0.0.0.0.1.0.1.1
.0.0.1.0.1.0.0.1
.0.1.1.1.1.0.0.0

Crossrefs

Sequence in context: A031290 A152908 A031386 * A106895 A106896 A097938

Adjacent sequences: A146810 A146811 A146812 * A146814 A146815 A146816

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved