A147009 Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 00100-11111-00100 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 3, 6, 13, 20, 35, 74, 191, 479, 1455, 4033, 12735, 40335, 153380, 583871

Offset

1,8

Links

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

Example

Maximal 8 X 8 example
.0.0.1.0.0.0.1.0
.1.1.1.1.1.0.1.0
.0.0.1.0.0.1.1.1
.0.1.0.0.0.0.1.0
.0.1.0.0.0.0.1.0
.1.1.1.0.0.1.0.0
.0.1.0.1.1.1.1.1
.0.1.0.0.0.1.0.0

Crossrefs

Sequence in context: A101965 A230370 A285246 * A361273 A318228 A064290

Adjacent sequences: A147006 A147007 A147008 * A147010 A147011 A147012

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved