A147250 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 11100-00100-00111 pattern in any orientation.

1, 1, 1, 1, 1, 3, 7, 15, 31, 125, 537, 2497, 11379, 73403, 564557, 5044749, 48150503, 565823439, 7944991263, 131881718303, 2468412664385

Offset

1,6

Links

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

Example

Maximal 8 X 8 example
.0.0.0.0.0.0.0.0
.0.0.1.1.1.0.0.0
.0.1.0.0.1.0.0.0
.0.1.0.0.1.1.1.0
.0.1.1.1.0.0.0.0
.0.0.0.1.0.0.0.0
.0.0.0.1.0.0.0.0
.0.0.0.0.0.0.0.0

Crossrefs

Sequence in context: A147094 A326518 A147285 * A336701 A066175 A132978

Adjacent sequences: A147247 A147248 A147249 * A147251 A147252 A147253

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved