A147477 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1100-1111-1100 pattern in any orientation.

1, 1, 1, 1, 1, 3, 9, 19, 52, 181, 742, 4149, 26078, 174469, 1396213, 13529455

Offset

1,6

Links

Table of n, a(n) for n=1..16.

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.0.0
.0.0.0.0.0.0.1.1
.0.0.0.0.1.1.1.1
.0.0.0.1.0.0.1.1
.0.0.0.1.0.0.0.0
.0.0.1.1.1.0.0.0
.0.0.1.1.1.0.0.0

Crossrefs

Sequence in context: A279682 A102001 A146901 * A146677 A077442 A147455

Adjacent sequences: A147474 A147475 A147476 * A147478 A147479 A147480

Keyword

nonn

Author

R. H. Hardin

Status

approved