A146283 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 111-110-111 pattern in any orientation.

1, 1, 1, 1, 1, 5, 13, 25, 59, 333, 1935, 9121, 45829, 402153, 4332077, 45059163, 497321737, 7788926343, 155218822227, 3328515197229, 77996266328591, 2325236376116081, 87368606923472999, 3749372750743895557

Offset

1,6

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.0.0.0.1.1.1
.0.0.0.0.0.0.1.1
.0.0.0.0.0.1.1.1
.0.0.0.0.0.0.0.0
.0.1.0.1.0.0.0.0
.0.1.1.1.0.0.0.0
.0.1.1.1.0.0.0.0

Crossrefs

Sequence in context: A147090 A097117 A146140 * A026373 A066885 A147151

Adjacent sequences: A146280 A146281 A146282 * A146284 A146285 A146286

Keyword

nonn

Author

R. H. Hardin

Status

approved