A146235 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 110-111-001 pattern in any orientation.

1, 1, 1, 1, 5, 17, 37, 167, 1407, 11143, 90213, 1212859, 22145521, 452553163, 11809473343, 424547990571, 19424907241691, 1100794820702881, 80980732651220757, 7763187679043412101, 948623501056895583231

Offset

1,5

Links

Table of n, a(n) for n=1..21.

Example

Maximal 8 X 8 example
.0.0.1.1.0.1.1.0
.0.0.1.1.0.0.1.1
.1.1.0.1.1.0.1.1
.1.1.1.0.0.1.0.0
.0.0.1.0.0.1.1.1
.1.0.0.1.1.0.1.1
.1.1.1.0.1.1.0.0
.0.1.1.0.1.1.0.0

Crossrefs

Sequence in context: A147181 A146850 A146428 * A087728 A072332 A212968

Adjacent sequences: A146232 A146233 A146234 * A146236 A146237 A146238

Keyword

nonn

Author

R. H. Hardin

Status

approved