A146701 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1100-1111-0010 pattern in any orientation.

1, 1, 1, 1, 1, 7, 21, 49, 229, 1181, 8807, 80469, 829699, 10398391, 167768019, 3412508539, 87515053777, 2785697640499, 108585173715039, 5239601524903617

Offset

1,6

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.1.1.0.0
.0.0.1.1.1.1.0.0
.0.1.0.1.0.0.1.1
.0.1.1.0.1.1.1.1
.1.1.0.1.0.1.0.0
.1.1.0.1.1.0.0.0
.0.0.1.1.0.0.0.0
.0.0.1.1.0.0.0.0

Crossrefs

Sequence in context: A163723 A146669 A146637 * A146613 A083012 A233329

Adjacent sequences: A146698 A146699 A146700 * A146702 A146703 A146704

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved