A144243 Number of n X n binary arrays, symmetric under 90-degree rotation, 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, 10, 36, 77, 170, 1539, 2778, 26239, 152082, 1317122, 7797811, 129473317, 857792500, 17986500145, 205469564882

Offset

1,2

Links

Table of n, a(n) for n=1..19.

Crossrefs

Sequence in context: A352418 A141486 A184344 * A125210 A098434 A212634

Adjacent sequences: A144240 A144241 A144242 * A144244 A144245 A144246

Keyword

nonn

Author

R. H. Hardin, Sep 15 2008

Status

approved