A146416 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1000-1111-1000 pattern in any orientation.

1, 1, 1, 1, 1, 3, 9, 21, 62, 243, 1174, 7129, 48787, 396149, 3872121, 46149825, 666105009, 11588188375, 240646188473, 5995766803300, 179504408659371, 6478981553440867, 281573700280824120, 14724253264482951366

Offset

1,6

Links

Table of n, a(n) for n=1..24.

Example

Maximal 8 X 8 example
.0.0.0.1.1.1.0.0
.0.0.0.0.1.0.1.0
.0.0.0.0.1.0.1.0
.1.0.0.0.1.0.1.0
.1.1.1.1.0.1.1.1
.1.0.0.0.1.0.0.0
.0.1.1.1.1.0.0.0
.0.0.0.0.1.0.0.0

Crossrefs

Sequence in context: A060578 A147078 A341704 * A260185 A307105 A239663

Adjacent sequences: A146413 A146414 A146415 * A146417 A146418 A146419

Keyword

nonn

Author

R. H. Hardin

Status

approved