A147341 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 0100-0100-1111-0010-0010 pattern in any orientation.

1, 1, 1, 1, 1, 1, 3, 9, 19, 39, 125, 481, 2209, 12179, 71971

Offset

1,7

Links

Table of n, a(n) for n=1..15.

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.0.0.0.1.0.0
.0.0.0.0.0.1.0.0
.0.0.0.0.1.1.1.1
.0.0.0.1.0.0.1.0
.0.1.1.1.0.0.1.0
.0.0.0.1.1.1.0.0
.0.0.0.1.0.0.0.0

Crossrefs

Sequence in context: A146819 A147213 A146441 * A208972 A307541 A268403

Adjacent sequences: A147338 A147339 A147340 * A147342 A147343 A147344

Keyword

nonn

Author

R. H. Hardin

Status

approved