A145775 Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only either two adjacent vertically or two adjacent horizontally.

1, 1, 1, 4, 10, 25, 98, 304, 1809, 7930, 72506, 400613, 5713422, 40142648, 888016669, 8057185631, 274304468798, 3201392865337, 169069430683773, 2534673576738596, 207045671219200314, 3988243193242437962, 504059170133969414707

Offset

1,4

Links

Table of n, a(n) for n=1..23.

Crossrefs

Sequence in context: A049348 A282389 A361611 * A283958 A335637 A255718

Adjacent sequences: A145772 A145773 A145774 * A145776 A145777 A145778

Keyword

nonn

Author

R. H. Hardin, Oct 18 2008

Status

approved