A223097 Number of n X n 0..2 arrays with exactly floor(n X n/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..2 order

1, 6, 546, 737254, 5423134897, 460895553576913, 178267875091681095647, 831156761247263067556854883, 16574854310429531539559558547925220

Offset

1,2

Comments

Diagonal of A223104

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for n=3
..0..0..0....0..1..2....0..1..0....0..1..0....0..1..1....0..1..2....0..1..2
..0..1..0....0..1..1....0..2..2....1..2..1....0..2..0....2..0..1....2..2..1
..2..1..0....2..2..1....1..1..2....0..0..2....0..2..2....0..1..2....2..0..1

Crossrefs

Sequence in context: A121835 A159531 A276490 * A213959 A358487 A341871

Adjacent sequences: A223094 A223095 A223096 * A223098 A223099 A223100

Keyword

nonn

Author

R. H. Hardin Mar 14 2013

Status

approved