A146926 Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 1001-1111-1001 pattern in any orientation.

1, 1, 1, 3, 3, 5, 9, 17, 89, 140, 1134, 2523, 20495, 73514, 534008, 1996987, 23508472, 92663083, 1862869380, 7762461636, 266742576438, 1312733745392, 59491047519251, 367850100364195, 19425750984998415, 144916187683650857

Offset

1,4

Links

Table of n, a(n) for n=1..26.

Example

Maximal 8 X 8 example
.1.1.1.0.0.1.1.1
.0.1.0.0.0.0.1.0
.0.1.0.0.0.0.1.0
.1.1.1.0.0.1.1.1
.0.0.0.0.0.0.0.0
.0.0.1.0.0.1.0.0
.0.0.1.1.1.1.0.0
.0.0.1.0.0.1.0.0

Crossrefs

Sequence in context: A325187 A209083 A137202 * A000198 A202674 A027170

Adjacent sequences: A146923 A146924 A146925 * A146927 A146928 A146929

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved