A144238 Number of n X n binary arrays, symmetric under horizontal and vertical reflection, with every 1 adjacent to at least one other 1 both bishopwise and rookwise but with no three 1s in a row bishopwise or rookwise.

1, 2, 1, 3, 2, 6, 14, 111, 56, 1337, 718, 24951, 27864, 1478458, 1080087, 130135921, 85888038, 18349790023, 15914995870, 5514906021024, 4665956204109

Offset

1,2

Links

Table of n, a(n) for n=1..21.

Crossrefs

Sequence in context: A206494 A022477 A238944 * A319622 A348747 A082833

Adjacent sequences: A144235 A144236 A144237 * A144239 A144240 A144241

Keyword

nonn

Author

R. H. Hardin, Sep 15 2008

Status

approved