A146851 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111-0001 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 1, 5, 13, 25, 45, 129, 391, 1245, 4737, 21985, 95961, 496289, 2673135, 16997063, 114065803

Offset

1,9

Links

Table of n, a(n) for n=1..22.

Example

Maximal 9 X 9 example
.0.0.0.0.0.1.1.0.0
.0.0.0.1.1.1.1.0.0
.0.0.0.1.0.0.0.1.1
.0.1.1.0.0.0.0.1.1
.0.1.0.0.0.0.0.1.0
.1.1.0.0.0.0.1.1.0
.1.1.0.0.0.1.0.0.0
.0.0.1.1.1.1.0.0.0
.0.0.1.1.0.0.0.0.0

Crossrefs

Sequence in context: A196069 A147182 A146175 * A146260 A147166 A146192

Adjacent sequences: A146848 A146849 A146850 * A146852 A146853 A146854

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved