A146920 Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 0110-1111-0110 pattern in any orientation.

1, 1, 1, 1, 1, 3, 7, 14, 36, 103, 399, 1984, 10103, 56582, 376480, 2975286, 28776438, 327464795, 4166314264, 60832319172, 1046036183155, 21253950128628, 511485269059218, 14299334912458273, 459782981526945170

Offset

1,6

Links

Table of n, a(n) for n=1..25.

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: A261051 A231397 A231464 * A079939 A147006 A146936

Adjacent sequences: A146917 A146918 A146919 * A146921 A146922 A146923

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved