A145762 Number of n X n binary arrays symmetric about the diagonal and under 90-degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.

1, 1, 1, 1, 2, 1, 4, 1, 11, 3, 36, 8, 178, 27, 1006, 96, 7478, 569, 70926, 4093, 898687, 37611, 14257237, 421080, 292647869, 6366190, 7706237478, 123605120, 263373760591, 3088656877

Offset

1,5

Links

Table of n, a(n) for n=1..30.

Crossrefs

Sequence in context: A243913 A186724 A145930 * A024539 A128271 A092891

Adjacent sequences: A145759 A145760 A145761 * A145763 A145764 A145765

Keyword

nonn

Author

R. H. Hardin, Oct 17 2008

Status

approved