A147243 Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1101-0111-0010 pattern in any orientation.

1, 1, 1, 1, 1, 1, 3, 5, 11, 21, 39, 109, 383, 1291, 5187, 19147, 85163, 418695, 2523925, 15886439, 116954773, 866328129

Offset

1,7

Links

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

Example

Maximal 8 X 8 example
.0.1.1.0.1.0.0.0
.1.0.1.1.1.0.0.0
.1.1.0.1.0.0.0.0
.0.1.1.0.0.0.1.1
.1.1.0.0.0.1.1.0
.0.0.0.0.1.0.1.1
.0.0.0.1.1.1.0.1
.0.0.0.1.0.1.1.0

Crossrefs

Sequence in context: A293317 A230097 A146787 * A372451 A192664 A122997

Adjacent sequences: A147240 A147241 A147242 * A147244 A147245 A147246

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved