A146737 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1110-0111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 17, 53, 309, 1493, 7269, 60637, 750031, 8947313, 159252711, 3162713321, 81850156841

Offset

1,6

Links

Table of n, a(n) for n=1..16.

Example

Maximal 8 X 8 example
.0.0.0.1.1.1.0.0
.0.0.1.1.1.0.0.0
.0.1.0.0.1.0.0.0
.0.1.1.1.0.1.1.1
.1.1.1.0.1.1.1.0
.0.0.0.1.0.0.1.0
.0.0.0.1.1.1.0.0
.0.0.1.1.1.0.0.0

Crossrefs

Sequence in context: A125637 A320897 A147255 * A146839 A147178 A146642

Adjacent sequences: A146734 A146735 A146736 * A146738 A146739 A146740

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved