A146685 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1100-1000-1111 pattern in any orientation.

1, 1, 1, 1, 3, 7, 19, 43, 167, 933, 5533, 35651, 275619, 2803985, 35280241, 511587387, 8841277573, 187861018789, 4919632132323, 154644209783001

Offset

1,5

Links

Table of n, a(n) for n=1..20.

Example

Maximal 8 X 8 example
.0.0.0.1.1.1.1.0
.0.0.0.1.0.0.0.0
.0.0.0.1.1.0.0.0
.1.1.1.0.0.1.1.1
.1.0.1.0.0.1.0.1
.1.0.0.1.1.0.0.1
.1.0.0.1.0.0.0.1
.0.0.0.1.1.1.1.0

Crossrefs

Sequence in context: A176500 A334099 A136041 * A146653 A096447 A274596

Adjacent sequences: A146682 A146683 A146684 * A146686 A146687 A146688

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved