A145763 Number of n X n binary arrays symmetric under 90-degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.

1, 1, 1, 1, 4, 7, 16, 35, 133, 363, 1590, 5600, 33892, 154647, 1163836, 6812622, 66760064, 504710757, 6331779830, 61565739001, 996948455181, 12487323542741, 259917683188595, 4189678086571772, 112326942697897637

Offset

1,5

Links

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

Crossrefs

Sequence in context: A108122 A192800 A027609 * A144916 A217289 A050357

Adjacent sequences: A145760 A145761 A145762 * A145764 A145765 A145766

Keyword

nonn

Author

R. H. Hardin, Oct 17 2008

Status

approved