A146919 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 0110-1111-0110 pattern in any orientation.

1, 1, 1, 1, 1, 1, 1, 4, 8, 13, 37, 82, 203, 410, 1390, 3260, 13938, 41809, 202082, 670860, 3891211

Offset

1,8

Links

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

Example

Maximal 8 X 8 example
.0.0.0.1.1.0.0.0
.0.0.1.1.1.1.0.0
.0.1.0.1.1.0.1.0
.1.1.1.0.0.1.1.1
.1.1.1.0.0.1.1.1
.0.1.0.1.1.0.1.0
.0.0.1.1.1.1.0.0
.0.0.0.1.1.0.0.0

Crossrefs

Sequence in context: A033016 A027008 A114997 * A312221 A312222 A312223

Adjacent sequences: A146916 A146917 A146918 * A146920 A146921 A146922

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved